Dissertations / Theses: 'Models of time travel'

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Lu, Chenxi. "Improving Analytical Travel Time Estimation for Transportation Planning Models." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/237.

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This dissertation aimed to improve travel time estimation for the purpose of transportation planning by developing a travel time estimation method that incorporates the effects of signal timing plans, which were difficult to consider in planning models. For this purpose, an analytical model has been developed. The model parameters were calibrated based on data from CORSIM microscopic simulation, with signal timing plans optimized using the TRANSYT-7F software. Independent variables in the model are link length, free-flow speed, and traffic volumes from the competing turning movements. The developed model has three advantages compared to traditional link-based or node-based models. First, the model considers the influence of signal timing plans for a variety of traffic volume combinations without requiring signal timing information as input. Second, the model describes the non-uniform spatial distribution of delay along a link, this being able to estimate the impacts of queues at different upstream locations of an intersection and attribute delays to a subject link and upstream link. Third, the model shows promise of improving the accuracy of travel time prediction. The mean absolute percentage error (MAPE) of the model is 13% for a set of field data from Minnesota Department of Transportation (MDOT); this is close to the MAPE of uniform delay in the HCM 2000 method (11%). The HCM is the industrial accepted analytical model in the existing literature, but it requires signal timing information as input for calculating delays. The developed model also outperforms the HCM 2000 method for a set of Miami-Dade County data that represent congested traffic conditions, with a MAPE of 29%, compared to 31% of the HCM 2000 method. The advantages of the proposed model make it feasible for application to a large network without the burden of signal timing input, while improving the accuracy of travel time estimation. An assignment model with the developed travel time estimation method has been implemented in a South Florida planning model, which improved assignment results.

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Sikder, Sujan. "Spatial Transferability of Activity-Based Travel Forecasting Models." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4771.

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Spatial transferability of travel forecasting models, or the ability to transfer models from one geographical region to another, can potentially help in significant cost and time savings for regions that cannot invest in extensive data-collection and model-development procedures. This issue is particularly important in the context of tour-based/activity-based models whose development typically involves significant data inputs, skilled staff, and long production times. However, most literature on model transferability has been in the context of traditionally used trip-based models, particularly for linear regression-based trip generation and logit-based mode choice models, with little evidence on the transferability of activity-based models and that of emerging model structures. The overarching goal of this dissertation is to assess the spatial transferability of activity-based travel demand models. To this end, the specific objectives are to: 1. Survey the literature to synthesize: (a) the approaches used to transfer models, (b) the metrics used to assess model transferability, (c) the available evidence on spatial transferability of travel models, and (d) notable gaps in literature; 2. Lay out a framework for assessing the spatial transferability of activity-based travel forecasting model systems, and evaluate alternative methods/metrics used for assessing the transferability of specific model components and their parameters; 3. Conduct empirical assessments of spatial transferability of the following two model components used in today's activity-based model systems: (a) daily activity participation and time-use models, and (b) tour-based time-of-day choice models. Data from the 2009 National Household Travel Survey (NHTS) and the 2000 San Francisco Bay Area Travel Survey (BATS) were used for these empirical assessments; 4. Conduct empirical assessments of model transferability using emerging model structures that have begun to be used in activity-based model systems - specifically the multiple discrete-continuous extreme value (MDCEV) model; 5. Investigate alternate ways of enhancing model transferability; specifically: (a) pooling data from different geographical regions, and (b) improvements to the model structure. The dissertation provides a framework for assessing the transferability of activity-based models systems, along with empirical evidence on the pros and cons of alternative methods and metrics of transferability assessment. The results suggest the need to consider model sensitivity to changes in explanatory variables as opposed to relying solely on the ability to predict aggregate distributions. Updating the constants of a transferred model using local data (a widely used method to transfer models) was found to help in increasing the model's ability to predict aggregate patterns but not necessarily in enhancing its sensitivity to changes in explanatory variables. Also, transferability assessments ought to consider sampling variance in parameter estimates as opposed to only the point estimates. Empirical analysis with the daily activity participation and time-use model shed new light on the prediction properties of the MDCEV model structure that have implications for model transferability. This led to the development of a new model structure called the multiple discrete continuous heteroscedastic extreme value (MDCHEV) model that incorporates heteroscedasticity in the model's stochastic distributions and helps in enhancing model transferability. Transferability assessment of the time-of-day choice models show encouraging evidence of transferability of a large proportion of the model coefficients, albeit except important parameters such as the travel time coefficients. Collectively, there is evidence that pooling data from multiple regions may help in building better transferable models than those transferred from a single region.

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Sidhu, Bobjot Singh. "Exploring Data Driven Models of Transit Travel Time and Delay." DigitalCommons@CalPoly, 2016. https://digitalcommons.calpoly.edu/theses/1601.

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Transit travel time and operating speed influence service attractiveness, operating cost, system efficiency and sustainability. The Tri-County Metropolitan Transportation District of Oregon (TriMet) provides public transportation service in the tri-county Portland metropolitan area. TriMet was one of the first transit agencies to implement a Bus Dispatch System (BDS) as a part of its overall service control and management system. TriMet has had the foresight to fully archive the BDS automatic vehicle location and automatic passenger count data for all bus trips at the stop level since 1997. More recently, the BDS system was upgraded to provide stop-level data plus 5-second resolution bus positions between stops. Rather than relying on prediction tools to determine bus trajectories (including stops and delays) between stops, the higher resolution data presents actual bus positions along each trip. Bus travel speeds and intersection signal/queuing delays may be determined using this newer information. This thesis examines the potential applications of higher resolution transit operations data for a bus route in Portland, Oregon, TriMet Route 14. BDS and 5-second resolution data from all trips during the month of October 2014 are used to determine the impacts and evaluate candidate trip time models. Comparisons are drawn between models and some conclusions are drawn regarding the utility of the higher resolution transit data. In previous research inter-stop models were developed based on the use of average or maximum speed between stops. We know that this does not represent realistic conditions of stopping at a signal/crosswalk or traffic congestion along the link. A new inter-stop trip time model is developed using the 5-second resolution data to determine the number of signals encountered by the bus along the route. The variability in inter-stop time is likely due to the effect of the delay superimposed by signals encountered. This newly developed model resulted in statistically significant results. This type of information is important to transit agencies looking to improve bus running times and reliability. These results, the benefits of archiving higher resolution data to understand bus movement between stops, and future research opportunities are also discussed.

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Jung, Sungyong. "Spatial variability of travel time coefficients in travel demand models and its implication for transportation equilibrium /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487758680162211.

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Yusuf, Adeel. "Advanced machine learning models for online travel-time prediction on freeways." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50408.

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The objective of the research described in this dissertation is to improve the travel-time prediction process using machine learning methods for the Advanced Traffic In-formation Systems (ATIS). Travel-time prediction has gained significance over the years especially in urban areas due to increasing traffic congestion. The increased demand of the traffic flow has motivated the need for development of improved applications and frameworks, which could alleviate the problems arising due to traffic flow, without the need of addition to the roadway infrastructure. In this thesis, the basic building blocks of the travel-time prediction models are discussed, with a review of the significant prior art. The problem of travel-time prediction was addressed by different perspectives in the past. Mainly the data-driven approach and the traffic flow modeling approach are the two main paths adopted viz. a viz. travel-time prediction from the methodology perspective. This dissertation, works towards the im-provement of the data-driven method. The data-driven model, presented in this dissertation, for the travel-time predic-tion on freeways was based on wavelet packet decomposition and support vector regres-sion (WPSVR), which uses the multi-resolution and equivalent frequency distribution ability of the wavelet transform to train the support vector machines. The results are compared against the classical support vector regression (SVR) method. Our results indi-cate that the wavelet reconstructed coefficients when used as an input to the support vec-tor machine for regression (WPSVR) give better performance (with selected wavelets on-ly), when compared against the support vector regression (without wavelet decomposi-tion). The data used in the model is downloaded from California Department of Trans-portation (Caltrans) of District 12 with a detector density of 2.73, experiencing daily peak hours except most weekends. The data was stored for a period of 214 days accumulated over 5 minute intervals over a distance of 9.13 miles. The results indicate an improvement in accuracy when compared against the classical SVR method. The basic criteria for selection of wavelet basis for preprocessing the inputs of support vector machines are also explored to filter the set of wavelet families for the WDSVR model. Finally, a configuration of travel-time prediction on freeways is present-ed with interchangeable prediction methods along with the details of the Matlab applica-tion used to implement the WPSVR algorithm. The initial results are computed over the set of 42 wavelets. To reduce the compu-tational cost involved in transforming the travel-time data into the set of wavelet packets using all possible mother wavelets available, a methodology of filtering the wavelets is devised, which measures the cross-correlation and redundancy properties of consecutive wavelet transformed values of same frequency band. An alternate configuration of travel-time prediction on freeways using the con-cepts of cloud computation is also presented, which has the ability to interchange the pre-diction modules with an alternate method using the same time-series data. Finally, a graphical user interface is described to connect the Matlab environment with the Caltrans data server for online travel-time prediction using both SVR and WPSVR modules and display the errors and plots of predicted values for both methods. The GUI also has the ability to compute forecast of custom travel-time data in the offline mode.

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Kachani, S. (Soulaymane). "Dynamic travel time models for pricing and route guidance : a fluid dynamics approach." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8527.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, 2002.
Includes bibliographical references (leaves 193-201).
This thesis investigates dynamic phenomena that arise in a variety of systems that share similar characteristics. A common characteristic of particular interest in this work is travel time. We wish to address questions of the type: How long does it take a driver to traverse a route in a transportation network? How long does a unit of product remain in inventory before being sold? As a result, our goal is not only to develop models for travel times as they arise in a variety of dynamically evolving environments, but also to investigate the application of these models in the contexts of dynamic pricing, inventory management, traffic control and route guidance. To address these issues, we develop general models for travel times. To make these models more accessible, we describe them as they apply to transportation systems. We propose first-order and second-order fluid models. We enhance these models to account for spillback and bottleneck phenomena. Based on piecewise linear and piecewise quadratic approximations of the departure or exit flows, we propose several classes of travel time functions. In the area of supply chain, we propose and study a fluid model of pricing and inventory management for make-to-stock manufacturing systems. This model is based on how price and level of inventory affect the time a unit of product remains in inventory. The model applies to non-perishable products. Our motivation is based on the observation that in inventory systems, a unit of product incurs a delay before being sold. This delay depends on the level of inventory of this product, its unit price, and prices of competitors.
(Cont.) The model includes joint pricing, production and inventory decisions in a competitive capacitated multi-product dynamic environment. Finally, we consider the anticipatory route guidance problem, an extension of the dynamic user-equilibrium problem. This problem consists of providing messages to drivers, based on forecasts of traffic conditions, to assist them in their path choice decisions. We propose two equivalent formulations that are the first general analytical formulations of this problem. We establish, under weak assumptions, the existence of a solution to this problem.
by Soulaymane Kachani.
Ph.D.

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Emam, Emam. "UTILIZING A REAL LIFE DATA WAREHOUSE TO DEVELOP FREEWAY TRAVEL TIME ELIABILITY STOCHASTIC MODELS." Doctoral diss., University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3987.

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During the 20th century, transportation programs were focused on the development of the basic infrastructure for the transportation networks. In the 21st century, the focus has shifted to management and operations of these networks. Transportation network reliability measure plays an important role in judging the performance of the transportation system and in evaluating the impact of new Intelligent Transportation Systems (ITS) deployment. The measurement of transportation network travel time reliability is imperative for providing travelers with accurate route guidance information. It can be applied to generate the shortest path (or alternative paths) connecting the origins and destinations especially under conditions of varying demands and limited capacities. The measurement of transportation network reliability is a complex issue because it involves both the infrastructure and the behavioral responses of the users. Also, this subject is challenging because there is no single agreed-upon reliability measure. This dissertation developed a new method for estimating the effect of travel demand variation and link capacity degradation on the reliability of a roadway network. The method is applied to a hypothetical roadway network and the results show that both travel time reliability and capacity reliability are consistent measures for reliability of the road network, but each may have a different use. The capacity reliability measure is of special interest to transportation network planners and engineers because it addresses the issue of whether the available network capacity relative to the present or forecast demand is sufficient, whereas travel time reliability is especially interesting for network users. The new travel time reliability method is sensitive to the users' perspective since it reflects that an increase in segment travel time should always result in less travel time reliability. And, it is an indicator of the operational consistency of a facility over an extended period of time. This initial theoretical effort and basic research was followed by applying the new method to the I-4 corridor in Orlando, Florida. This dissertation utilized a real life transportation data warehouse to estimate travel time reliability of the I-4 corridor. Four different travel time stochastic models: Weibull, Exponential, Lognormal, and Normal were tested. Lognormal was the best-fit model. Unlike the mechanical equipments, it is unrealistic that any freeway segment can be traversed in zero seconds no matter how fast the vehicles are. So, an adjustment of the developed best-fit statistical model (Lognormal) location parameter was needed to accurately estimate the travel time reliability. The adjusted model can be used to compute and predict travel time reliability of freeway corridors and report this information in real time to the public through traffic management centers. Compared to existing Florida Method and California Buffer Time Method, the new reliability method showed higher sensitivity to geographical locations, which reflects the level of congestion and bottlenecks. The major advantages/benefits of this new method to practitioners and researchers over the existing methods are its ability to estimate travel time reliability as a function of departure time, and that it treats travel time as a continuous variable that captures the variability experienced by individual travelers over an extended period of time. As such, the new method developed in this dissertation could be utilized in transportation planning and freeway operations for estimating the important travel time reliability measure of performance. Then, the segment length impacts on travel time reliability calculations were investigated utilizing the wealth of data available in the I-4 data warehouse. The developed travel time reliability models showed significant evidence of the relationship between the segment length and the results accuracy. The longer the segment, the less accurate were the travel time reliability estimates. Accordingly, long segments (e.g., 25 miles) are more appropriate for planning purposes as a macroscopic performance measure of the freeway corridor. Short segments (e.g., 5 miles) are more appropriate for the evaluation of freeway operations as a microscopic performance measure. Further, this dissertation has explored the impact of relaxing an important assumption in reliability analysis: Link independency. In real life, assuming that link failures on a road network are statistically independent is dubious. The failure of a link in one particular area does not necessarily result in the complete failure of the neighboring link, but may lead to deterioration of its performance. The "Cause-Based Multimode Model" (CBMM) has been used to address link dependency in communication networks. However, the transferability of this model to transportation networks has not been tested and this approach has not been considered before in the calculation of transportation networks' reliability. This dissertation presented the CBMM and applied it to predict transportation networks' travel time reliability that an origin demand can reach a specified destination under multimodal dependency link failure conditions. The new model studied the multi-state system reliability analysis of transportation networks for which one cannot formulate an "all or nothing" type of failure criterion and in which dependent link failures are considered. The results demonstrated that the newly developed method has true potential and can be easily extended to large-scale networks as long as the data is available. More specifically, the analysis of a hypothetical network showed that the dependency assumption is very important to obtain more reasonable travel time reliability estimates of links, paths, and the entire network. The results showed large discrepancy between the dependency and independency analysis scenarios. Realistic scenarios that considered the dependency assumption were on the safe side, this is important for transportation network decision makers. Also, this could aid travelers in making better choices. In contrast, deceptive information caused by the independency assumption could add to the travelers' anxiety associated with the unknown length of delay. This normally reflects negatively on highway agencies and management of taxpayers' resources.
Ph.D.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering

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Tringides, Constantinos A. "Alternative formulations of joint model systems of departure time choice and mode choice for non-work trips." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000240.

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Nehra, Ram S. "Modeling time space prism constraints in a developing country context." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000299.

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Yang, Shu, and Shu Yang. "Estimating Freeway Travel Time Reliability for Traffic Operations and Planning." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/623003.

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Travel time reliability (TTR) has attracted increasing attention in recent years, and is often listed as one of the major roadway performance and service quality measures for both traffic engineers and travelers. Measuring travel time reliability is the first step towards improving travel time reliability, ensuring on-time arrivals, and reducing travel costs. Four components may be primarily considered, including travel time estimation/collection, quantity of travel time selection, probability distribution selection, and TTR measure selection. Travel time is a key transportation performance measure because of its diverse applications and it also serves the foundation of estimating travel time reliability. Various modelling approaches to estimating freeway travel time have been well developed due to widespread installation of intelligent transportation system sensors. However, estimating accurate travel time using existing freeway travel time models is still challenging under congested conditions. Therefore, this study aimed to develop an innovative freeway travel time estimation model based on the General Motors (GM) car-following model. Since the GM model is usually used in a micro-simulation environment, the concepts of virtual leading and virtual following vehicles are proposed to allow the GM model to be used in macro-scale environments using aggregated traffic sensor data. Travel time data collected from three study corridors on I-270 in St. Louis, Missouri was used to verify the estimated travel times produced by the proposed General Motors Travel Time Estimation (GMTTE) model and two existing models, the instantaneous model and the time-slice model. The results showed that the GMTTE model outperformed the two existing models due to lower mean average percentage errors of 1.62% in free-flow conditions and 6.66% in two congested conditions. Overall, the GMTTE model demonstrated its robustness and accuracy for estimating freeway travel times. Most travel time reliability measures are derived directly from continuous probability distributions and applied to the traffic data directly. However, little previous research shows a consensus of probability distribution family selection for travel time reliability. Different probability distribution families could yield different values for the same travel time reliability measure (e.g. standard deviation). It is believe that the specific selection of probability distribution families has few effects on measuring travel time reliability. Therefore, two hypotheses are proposed in hope of accurately measuring travel time reliability. An experiment is designed to prove the two hypotheses. The first hypothesis is proven by conducting the Kolmogorov–Smirnov test and checking log-likelihoods, and Akaike information criterion with a correction for finite sample sizes (AICc) and Bayesian information criterion (BIC) convergences; and the second hypothesis is proven by examining both moment-based and percentile-based travel time reliability measures. The results from the two hypotheses testing suggest that 1) underfitting may cause disagreement in distribution selection, 2) travel time can be precisely fitted using mixture models with higher value of the number of mixture distributions (K), regardless of the distribution family, and 3) the travel time reliability measures are insensitive to the selection of distribution family. Findings of this research allows researchers and practitioners to avoid the work of testing various distributions, and travel time reliability can be more accurately measured using mixture models due to higher value of log-likelihoods. As with travel time collection, the accuracy of the observed travel time and the optimal travel time data quantity should be determined before using the TTR data. The statistical accuracy of TTR measures should be evaluated so that the statistical behavior and belief can be fully understood. More specifically, this issue can be formulated as a question: using a certain amount of travel time data, how accurate is the travel time reliability for a specific freeway corridor, time of day (TOD), and day of week (DOW)? A framework for answering this question has not been proposed in the past. Our study proposes a framework based on bootstrapping to evaluate the accuracy of TTR measures and answer the question. Bootstrapping is a computer-based method for assigning measures of accuracy to multiple types of statistical estimators without requiring a specific probability distribution. Three scenarios representing three traffic flow conditions (free-flow, congestion, and transition) were used to fully understand the accuracy of TTR measures under different traffic conditions. The results of the accuracy measurements primarily showed that: 1) the proposed framework can facilitate assessment of the accuracy of TTR, and 2) stabilization of the TTR measures did not necessarily correspond to statistical accuracy. The findings in our study also suggested that moment-based TTR measures may not be statistically sufficient for measuring freeway TTR. Additionally, our study suggested that 4 or 5 weeks of travel time data is enough for measuring freeway TTR under free-flow conditions, 40 weeks for congested conditions, and 35 weeks for transition conditions. A considerable number of studies have contributed to measuring travel time reliability. Travel time distribution estimation is considered as an important starting input of measuring travel time reliability. Kernel density estimation (KDE) is used to estimate travel time distribution, instead of parametric probability distributions, e.g. Lognormal distribution, the two state models. The Hasofer Lind - Rackwitz Fiessler (HL-RF) algorithm, widely used in the field of reliability engineering, is applied to this work. It is used to compute the reliability index of a system based on its previous performance. The computing procedure for travel time reliability of corridors on a freeway is first introduced. Network travel time reliability is developed afterwards. Given probability distributions estimated by the KDE technique, and an anticipated travel time from travelers, the two equations of the corridor and network travel time reliability can be used to address the question, "How reliable is my perceived travel time?" The definition of travel time reliability is in the sense of "on time performance", and it is conducted inherently from the perspective of travelers. Further, the major advantages of the proposed method are: 1) The proposed method demonstrates an alternative way to estimate travel time distributions when the choice of probability distribution family is still uncertain; 2) the proposed method shows its flexibility for being applied onto different levels of roadways (e.g. individual roadway segment or network). A user-defined anticipated travel time can be input, and travelers can utilize the computed travel time reliability information to plan their trips in advance, in order to better manage trip time, reduce cost, and avoid frustration.

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Silva, Francisco Gildemir Ferreira da. "Modeling value of travel time to competitors by different ways logit models: what you win and lose that?" Universidade Federal do CearÃ, 2011. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=7352.

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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
Economists since 1965 search a way to measure the value of time. This paper addresses empirical results from a theoretical background proposed in the particular case of transport. The Tuong and Hensher (1985) paper unified the theory and empirical measurement however, over the years various methods for estimation of discrete choice models were not used to measure the values of travel time. This thesis measures the value of travel time of the intercity transport users in CearÃ using four models: unstructured type McFadden and the other three, as proposed in Tuong and Hensher (1985a) (Becker, and DeSerpa and Tuong Hensher via Taylor expansion). Additional to the traditional logit model, it estimates the same models using the methodology developed by Morikawa (1989) and simulated maximum likelihood estimation and Bayesian to logit models like in Train (2003). The result indicates that it should use the estimation methods and different functional forms sparingly, because depending on the parameters obtained can be found values for travel time considerably different. On the other hand, the functional forms can be good for prediction. A choice of estimation methods such as enrichment suggests less distortion from standard model. A choice of functional form indicates the use the model of Becker or DeSerpa because of their small oscillation regardless of the estimation methods used. Already a combined choice of estimation method and functional form suggests Becker or DeSerpa with Simulated Maximum Likelihood estimation to obtain values of travel time and to forecasts.
Economistas desde 1965 debruÃam-se sobre uma forma de como mensurar o valor do tempo. O trabalho de Tuong e Hensher (1985) uniu teoria ao empirismo, entretanto, com o passar dos anos os mÃtodos diversos de estimaÃÃo por modelos de escolha discreta nÃo foram utilizados para a mediÃÃo do valor de tempo de viagem. Esta tese mensura o valor de tempo de viagem dos usuÃrios de transporte intermunicipal no CearÃ utilizando de quatro modelos: nÃo estruturado tipo McFadden e os outros trÃs, conforme proposto em Tuong e Hensher (1985a), para Becker, DeSerpa e a proposta de Tuong e Hensher via expansÃo de Taylor. Adicional ao modelo logit tradicional, faz-se estimaÃÃes das mesmas formas funcionais utilizando da metodologia desenvolvida por Morikawa (1989) e depois a de estimaÃÃes de mÃxima verossimilhanÃa simulada e bayesiana para modelo logit com fatores aleatÃrios apresentada em Train (2003). O resultado indica que se devem utilizar os mÃtodos de estimaÃÃo e formas funcionais distintas com parcimÃnia, pois dependendo dos parÃmetros obtidos, podem ser encontrados valores para tempo de viagem consideravelmente diferente. Por outro lado, as formas funcionais podem ser boas para previsÃo tal como discutido acima. Uma escolha entre mÃtodos de estimaÃÃo sugere o enriquecimento como o que menos distorce as estimativas do logit padrÃo. Uma escolha de forma funcional indica o uso do modelo de Becker ou do DeSerpa por conta da sua pequena oscilaÃÃo independentemente dos mÃtodos de estimaÃÃo utilizados. JÃ uma escolha combinada entre mÃtodo de estimaÃÃo e forma funcional sugere o modelo de Becker e DeSerpa com MÃxima VerossimilhanÃa Simulada, tanto para obter valores de tempo de viagem como para prever eventos.

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Wang, Zhuojin. "Incident-Related Travel Time Estimation Using a Cellular Automata Model." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/33644.

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The purpose of this study was to estimate the driversâ travel time with the occurrence of an incident on freeway. Three approaches, which were shock wave analysis, queuing theory and cellular automata models, were initially considered, however, the first two macroscopic models were indicated to underestimate travel time by previous literature. A microscopic simulation model based on cellular automata was developed to attain the goal. The model incorporated driving behaviors on the freeway with the presence of on-ramps, off-ramps, shoulder lanes, bottlenecks and incidents. The study area was a 16 mile eastbound section of I-66 between US-29 and I-495 in northern Virginia. The data for this study included loop detector data and incident data for the road segment for the year 2007. Flow and speed data from the detectors were used for calibration using quantitative and qualitative techniques. The cellular automata model properly reproduced the traffic flow under normal conditions and incidents. The travel time information was easily obtained from the model. The system is promising for travel time estimation in near real time.
Master of Science

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Sanz, Prat Alicia [Verfasser], and Olaf [Akademischer Betreuer] Cirpka. "Validation of Travel- and Exposure-Time Based Nonlinear Reactive Transport Models / Alicia Sanz Prat ; Betreuer: Olaf Cirpka." Tübingen : Universitätsbibliothek Tübingen, 2016. http://d-nb.info/1198120940/34.

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Sanz-Prat, Alicia [Verfasser], and Olaf [Akademischer Betreuer] Cirpka. "Validation of Travel- and Exposure-Time Based Nonlinear Reactive Transport Models / Alicia Sanz Prat ; Betreuer: Olaf Cirpka." Tübingen : Universitätsbibliothek Tübingen, 2016. http://d-nb.info/1198120940/34.

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Zhou, Zhong. "Models and Algorithms for Addressing Travel Time Variability: Applications from Optimal Path Finding and Traffic Equilibrium Problems." DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/129.

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An optimal path finding problem and a traffic equilibrium problem are two important, fundamental, and interrelated topics in the transportation research field. Under travel time variability, the road networks are considered as stochastic, where the link travel times are treated as random variables with known probability density functions. By considering the effect of travel time variability and corresponding risk-taking behavior of the travelers, this dissertation proposes models and algorithms for addressing travel time variability with applications from optimal path finding and traffic equilibrium problems. Specifically, two new optimal path finding models and two novel traffic equilibrium models are proposed in stochastic networks. To adaptively determine a reliable path with the minimum travel time budget required to meet the user-specified reliability threshold α, an adaptive α-reliable path finding model is proposed. It is formulated as a chance constrained model under a dynamic programming framework. Then, a discrete-time algorithm is developed based on the properties of the proposed model. In addition to accounting for the reliability aspect of travel time variability, the α-reliable mean-excess path finding model further concerns the unreliability aspect of the late trips beyond the travel time budget. It is formulated as a stochastic mixed-integer nonlinear program. To solve this difficult problem, a practical double relaxation procedure is developed. By recognizing travelers are not only interested in saving their travel time but also in reducing their risk of being late, a α-reliable mean-excess traffic equilibrium (METE) model is proposed. Furthermore, a stochastic α-reliable mean-excess traffic equilibrium (SMETE) model is developed by incorporating the travelers’ perception error, where the travelers’ route choice decisions are determined by the perceived distribution of the stochastic travel time. Both models explicitly examine the effects of both reliability and unreliability aspects of travel time variability in a network equilibrium framework. They are both formulated as a variational inequality (VI) problem and solved by a route-based algorithm based on the modified alternating direction method. In conclusion, this study explores the effects of the various aspects (reliability and unreliability) of travel time variability on travelers’ route choice decision process by considering their risk preferences. The proposed models provide novel views of the optimal path finding problem and the traffic equilibrium problem under an uncertain environment, and the proposed solution algorithms enable potential applicability for solving practical problems.

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Aldokhayel, Abdulaziz. "A Kalman Filter-based Dynamic Model for Bus Travel Time Prediction." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/38060.

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Urban areas are currently facing challenges in terms of traffic congestion due to city expansion and population increase. In some cases, physical solutions are limited. For example, in certain areas it is not possible to expand roads or build a new bridge. Therefore, making public transpiration (PT) affordable, more attractive and intelligent could be a potential solution for these challenges. Accuracy in bus running time and bus arrival time is a key component of making PT attractive to ridership. In this thesis, a dynamic model based on Kalman filter (KF) has been developed to predict bus running time and dwell time while taking into account real-time road incidents. The model uses historical data collected by Automatic Vehicle Location system (AVL) and Automatic Passenger Counters (APC) system. To predict the bus travel time, the model has two components of running time prediction (long and short distance prediction) and dwell time prediction. When the bus closes its doors before leaving a bus stop, the model predicts the travel time to all downstream bus stops. This is long distance prediction. The model will then update the prediction between the bus’s current position and the upcoming bus stop based on real-time data from AVL. This is short distance prediction. Also, the model predicts the dwell time at each coming bus stop. As a result, the model reduces the difference between the predicted arrival time and the actual arrival time and provides a better understanding for the transit network which allows lead to have a good traffic management.

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Li, Lok-man Jennifer, and 李諾文. "Schedule delay of work trips in Hong Kong: anempirical analysis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B40988041.

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Wu, Seung Kook. "Adaptive traffic control effect on arterial travel time charateristics." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31839.

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Thesis (Ph.D)--Civil and Environmental Engineering, Georgia Institute of Technology, 2010.
Committee Chair: Hunter, Michael; Committee Member: Guensler, Randall; Committee Member: Leonard, John; Committee Member: Rodgers, Michael; Committee Member: Roshan J. Vengazhiyil. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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Al, Adaileh Mohammad Ali. "A Travel Time Estimation Model for Facility Location on Real Road Networks." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1557421387196019.

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Seshadri, Anand. "A Model to Assess the Mobility of the National Airpspace System (NAS)." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/30777.

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One of the ways to define mobility in a transportation system is total travel time for all travelers using the transportation network. A good assessment of the mobility is essential for knowing the points of congestion in the network and the factors responsible for the congestion. Also the change in mobility from the baseline to the horizon year would give the modeler an idea of the effectiveness of the various transportation systems. One of the applications of the mobility measurement is the evaluation of aviation technologies proposed by FAA to ease the congestion. This paper addresses a method to estimate the mobility of the air transportation network in the baseline year (2000). Also presented is a method to estimate the mobility to the horizon year by considering congestion on the roadway.
Master of Science

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21

Justen, Andreas. "A time-space constrained approach for modeling travel and activity patterns." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2011. http://dx.doi.org/10.18452/16378.

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Gegenstand der Arbeit ist die Entwicklung eines tour-basierten Verkehrsnachfragemodells zur Abbildung von Aktivitätenketten unter Berücksichtigung von raum-zeitlichen constraints. Den theoretischen Hintergrund bildet ein hierarchisch organisierter Entscheidungsprozess, um die theoretisch möglichen Entscheidungskombinationen zu reduzieren und damit eine wahrscheinlichkeitsbasierte Berechnung zu ermöglichen. Als Beispieltour dient die Aktivitätenkette ‚Wohnen-Arbeit-Sekundäraktivität-Wohnen’, auf deren Basis auch die statistischen Analysen der Mobilitätsbefragung Santiagos durchgeführt werden. Unter Verwendung eines GIS werden so genannte ‚Suchräume’ (Aktionsräume in denen Sekundäraktivitäten durchgeführt werden) ermittelt. Ein Ergebnis der Datenanalyse sind Grenzwerte der maximalen täglichen Reisezeit für eine Reihe von Modus-Kombinationen. Die Zeitfenster von Startzeiten und Aktivitätendauer werden in Abhängigkeit sozioökonomischer Gruppen ermittelt. Die Bestimmung der Suchräume erfolgt in Abhängigkeit von Arbeitsdauer sowie Distanz zwischen Wohn- und Arbeitsort. Beide Kriterien erwiesen sich in der Analyse als statistisch signifikant. Der Vergleich zwischen Modell und Empirie (Santiagos Mobilitätsbefragung) deutet darauf hin, dass die Suchräume geeignet sind und die Mehrheit der beobachteten Zielwahlentscheidungen beinhalten. Zur Berechnung der Wahrscheinlichkeitspfade (unter Verwendung der Programmsyntax von SPSS) wird ein im Umfang auf sieben Ziele reduziertes Alternativenset pro Wohn- und Arbeitsstandort bestimmt. Dabei werden Erreichbarkeit und Attraktivität der Ziele innerhalb des Suchraumes berücksichtigt. Die erzielten Ergebnisse stützen das Argument, dass die raum-zeitlichen constraints (tägliche Reisezeit, Suchräume) eine effektive Reduktion der kombinatorischen Vielfalt zulassen. Die Erfahrungen aus der Berechnung der Beispieltour eignen sich zum Übertrag auf weitere Tour-Typen, um eine Modellierung der städtischen Gesamtverkehrsnachfrage zu ermöglichen.
In this thesis we develop a tour-based approach for modeling activity and travel pattern considering time-space constraints. A hierarchical structure of choice-making builds theoretical background for the model and is based on a set of axiomatic rules. Our central argument is that the time-space constraints can be used for reducing the number of choices and, respectively, control the combinatorics associated with the probabilistic approach. The empirical analysis of our use case, a tour of type ‘Home-Work-SecondaryActivity-Home’, is based on Santiago’s travel survey. In addition, we apply GIS to estimate the so-called search spaces (potential areas where secondary activities are realized) and justify their sizes with the empirical findings. From the data analysis we identify thresholds for the tour-based maximum daily travel times considering a set of mode combinations. We define regimes of starting times and duration of activities depending on socio-economic user groups. The estimation of search spaces is realized considering the time spent at work as well as the distance between the home and work locations. Both criteria were found to be statistically significant. The comparison of modeled results with survey observations allowed concluding that the search spaces are realistic since they capture most of the observed trip destinations. For the estimation of spatial path flows of activities and trips (using SPSS programming language), we define a final choice set of no more than seven alternatives per primary location considering zone-based accessibility and land-use attractiveness. The obtained results support the argument that time-space constraints (daily travel time, search spaces) allow an effective control of combinatorial complexity. Basing on the experience obtained in process of modeling the exemplary tour, the approach can be applied to further tour types offering the possibility to estimate the entire transport demand of Santiago city.

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Rhodes, Mark. "Mantle seismic tomography using P-wave travel times and a priori velocity models." Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266489.

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Mantle seismic tomography has historically relied on radially symmetric ID velocity models to trace ray paths through the mantle. The resulting travel time residuals are used to invert for seismic velocity perturbations around this 1D model. However, we know the Earth deviates from such ID velocity models; for example there are global variations in crustal thickness; in the age of oceanic lithosphere and presence of subducting oceanic lithosphere. In light of this, an a priori model which incorporated the three types of surface observable heterogeneity outlined above was constructed as part of this thesis. Tracing ray paths through this more heterogeneous starting model resulted in new travel time residuals which were subsequently employed in a simultaneous tomographic inversion solving for earthquake relocation parameters and slowness perturbations. This inversion method allows us to investigate whether tomography using a priori models results in improved images of mantle velocity perturbations and systematic earthquake relocations. A graphical earthquake browser was specifically written to establish, in a consistent manner, the shape of subducting oceanic lithosphere for all the major subduction zones. The resulting population of earthquakes, which best represent the shape of Wadati-Benioff zones, were subsequently interpolated into profiles following the path of oceanic lithosphere as it subducts. The temperature field in and around each profile was generated using a new analytic solution of the heat equation for subducting lithosphere, adapted to incorporate slab shape. The upper mantle a priori model was constructed on an equal area tomographic grid by combining the thermal models of the subducting lithosphere, plate cooling models of oceanic lithosphere and variations in crustal thickness away from that prescribed in a ID velocity model. Efficient 20 ray tracing through the a priori model was achieved via the adaptation of a ID ray tracer by perturbing the reference ID model, iasp91, using the a priori velocities in the cells connecting the event to the recording station for each ray. A new travel time residual was calculated and subsequently used in the simultaneous solution for slowness perturbation and earthquake relocation. So as not to bias the earthquake relocation procedure, phases were selected so as to maximise the azimuth and epicentral distance coverage, while minimising the number of duplicated ray paths which would be redundant in the inversion. The data selection resulted in some 3,450 events emitting 785,000 teleseismic P phases (bottoming in the lower mantle). The cell based SIRT inversion procedure, used to solve the standard system of linear tomographic equations, was augmented by explicit damping and smoothing matrices so as to control both poorly resolved cells and the relative importance between earthquake relocation parameters and slowness perturbations. For comparison, the ray population was also traced through the 3SMAC upper mantle model before undertaking a similar inversion. The 5° x 5° equal area, 100 km thick, cell inversions resulted in systematic earthquake relocations with an average relocation distance of= 5 km. In the upper mantle, the inversion procedure adjusts the a priori subducting slab velocity contrast, revealing images of subducting oceanic lithosphere. In the lower mantle, there is little difference between inversions produced in this thesis and those available digitally. Some of the main features are the pronounced lineations interpreted as the Farallon slab (beneath North and South America) and the Tethys (beneath Eurasia) clearly imaged between 1200 and 1500 km depth. All inversions undertaken in this thesis image hotspots throughout the upper mantle, and in places these pronounced slow features are observed passing through the upperllower mantle transition. A section through the South Pacific superswell images slow material as a continuous body, to at least 1300 km. Synthetic recovery tests indicate these hotspot features are well resolved.

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Dörr, Katharina [Verfasser]. "Travel Time Models and Throughput Analysis of Dual Load Handling Automated Storage and Retrieval Systems in Double Deep Storage / Katharina Dörr." Karlsruhe : KIT Scientific Publishing, 2018. http://www.ksp.kit.edu.

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Kondyli, Alexandra. "Development of an arterial link travel time model with consideration of mid-block delays." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0013260.

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Seybold, Christoph. "Calibration of fundamental diagrams for travel time predictions based on the cell transmission model." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-118577.

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Road traffic increases constantly and the negative consequences in the form of traffic jams can be realized especially in urban areas. In order to provide real time traffic information to road users and traffic managers, accurate computer models gain relevance. A software called Mobile Millennium Stockholm (MMS) was developed to estimate and predict travel times and has been implemented on a 7km test stretch in the north of Stockholm. The core of the software is the cell transmission model (CTM) which is a macroscopic traffic flow model based on aggregated speed observations. This thesis focuses on different calibration techniques of the so called fundamental diagram as an important input factor to the CTM. The diagrams illustrate the mathematical function which defines the relation between traffic flow, density and speed. The calibration is performed in different scenarios based on the least square (LS) and total least square (TLS) error minimization. Furthermore, sources, representing the traffic demand, and sinks, representing the surrounding of the modeled network, are implemented as dynamic parameters to model the change in traffic behavior throughout the day. Split ratios, as a representation of the drivers route choice in the CTM are estimated and implemented as well. For the framework of this work, the MMS software is run in a pure prediction mode. The CTM is based on the source, sink, split and fundamental diagram parameters only and run forward in time. For each fundamental diagram calibration scenario an independent model run is performed. The evaluation of the scenarios is based on the output of the model. The results are compared to existing Bluetooth travel time measurements for the test stretch, which are used as ground truth observations, and a mean average percentage error (MAPE) is calculated. This leads to a most reasonable technique for the fundamental diagram calibration the total least square error minimization.

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Chen, Hao. "Real-time Traffic State Prediction: Modeling and Applications." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/64292.

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Travel-time information is essential in Advanced Traveler Information Systems (ATISs) and Advanced Traffic Management Systems (ATMSs). A key component of these systems is the prediction of the spatiotemporal evolution of roadway traffic state and travel time. From the perspective of travelers, such information can result in better traveler route choice and departure time decisions. From the transportation agency perspective, such data provide enhanced information with which to better manage and control the transportation system to reduce congestion, enhance safety, and reduce the carbon footprint of the transportation system. The objective of the research presented in this dissertation is to develop a framework that includes three major categories of methodologies to predict the spatiotemporal evolution of the traffic state. The proposed methodologies include macroscopic traffic modeling, computer vision and recursive probabilistic algorithms. Each developed method attempts to predict traffic state, including roadway travel times, for different prediction horizons. In total, the developed multi-tool framework produces traffic state prediction algorithms ranging from short – (0~5 minutes) to medium-term (1~4 hours) considering departure times up to an hour into the future. The dissertation first develops a particle filter approach for use in short-term traffic state prediction. The flow continuity equation is combined with the Van Aerde fundamental diagram to derive a time series model that can accurately describe the spatiotemporal evolution of traffic state. The developed model is applied within a particle filter approach to provide multi-step traffic state prediction. The testing of the algorithm on a simulated section of I-66 demonstrates that the proposed algorithm can accurately predict the propagation of shockwaves up to five minutes into the future. The developed algorithm is further improved by incorporating on- and off-ramp effects and more realistic boundary conditions. Furthermore, the case study demonstrates that the improved algorithm produces a 50 percent reduction in the prediction error compared to the classic LWR density formulation. Considering the fact that the prediction accuracy deteriorates significantly for longer prediction horizons, historical data are integrated and considered in the measurement update in the developed particle filter approach to extend the prediction horizon up to half an hour into the future. The dissertation then develops a travel time prediction framework using pattern recognition techniques to match historical data with real-time traffic conditions. The Euclidean distance is initially used as the measure of similarity between current and historical traffic patterns. This method is further improved using a dynamic template matching technique developed as part of this research effort. Unlike previous approaches, which use fixed template sizes, the proposed method uses a dynamic template size that is updated each time interval based on the spatiotemporal shape of the congestion upstream of a bottleneck. In addition, the computational cost is reduced using a Fast Fourier Transform instead of a Euclidean distance measure. Subsequently, the historical candidates that are similar to the current conditions are used to predict the experienced travel times. Test results demonstrate that the proposed dynamic template matching method produces significantly better and more stable prediction results for prediction horizons up to 30 minutes into the future for a two hour trip (prediction horizon of two and a half hours) compared to other state-of-the-practice and state-of-the-art methods. Finally, the dissertation develops recursive probabilistic approaches including particle filtering and agent-based modeling methods to predict travel times further into the future. Given the challenges in defining the particle filter time update process, the proposed particle filtering algorithm selects particles from a historical dataset and propagates particles using data trends of past experiences as opposed to using a state-transition model. A partial resampling strategy is then developed to address the degeneracy problem in the particle filtering process. INRIX probe data along I-64 and I-264 from Richmond to Virginia Beach are used to test the proposed algorithm. The results demonstrate that the particle filtering approach produces less than a 10 percent prediction error for trip departures up to one hour into the future for a two hour trip. Furthermore, the dissertation develops an agent-based modeling approach to predict travel times using real-time and historical spatiotemporal traffic data. At the microscopic level, each agent represents an expert in the decision making system, which predicts the travel time for each time interval according to past experiences from a historical dataset. A set of agent interactions are developed to preserve agents that correspond to traffic patterns similar to the real-time measurements and replace invalid agents or agents with negligible weights with new agents. Consequently, the aggregation of each agent's recommendation (predicted travel time with associated weight) provides a macroscopic level of output – predicted travel time distribution. The case study demonstrated that the agent-based model produces less than a 9 percent prediction error for prediction horizons up to one hour into the future.
Ph. D.

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Ghimire, Ekaraj. "Evaluation of One-Dimensional and Two-Dimensional HEC-RAS Models for Flood Travel Time Prediction and Damage Assessment Using HAZUS-MH: A Case Study of Grand River, Ohio." Youngstown State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1558558269011099.

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28

Hössinger, Reinhard, Florian Aschauer, Sergio Jara-Díaz, Simona Jokubauskaite, Basil Schmid, Stefanie Peer, Kay W. Axhausen, and Regine Gerike. "A joint time-assignment and expenditure-allocation model: value of leisure and value of time assigned to travel for specific population segments." Springer, 2019. http://dx.doi.org/10.1007/s11116-019-10022-w.

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Based on a time-use model with a sound theoretical basis and carefully collected data for Austria, the value of leisure (VoL) for different population segments has been estimated. Through the combination of these results with mode-specific values of travel time savings from a related study based on the same data, the first mode-specific values of time assigned to travel (VTAT) were calculated. Data was collected using a Mobility-Activity-Expenditure Diary, a novel survey format which gathers all activities, expenditures, and travel decisions from the same individuals for 1 week in a diary-based format. The average VoL is 8.17 Euro/h, which is below the mean wage of 12.14 Euro/h, indicating that the value of work is, on average, negative. Regarding the reliability of the VoL, we show its sensitivity to the variance of working time in a sample, something that has been ignored in previous studies and could be used to avoid inadequate segmentation. We controlled this effect in the analysis of the heterogeneity of the VoL across the population by estimating the parameters from the total (unsegmented) dataset with single interaction terms. We find that the VTAT is strictly negative for walking, predominantly negative for cycling and car, and predominantly positive for public transport with 0.27 Euro/h on average. The positive VTAT for public transport is a strong indication for the importance of travel conditions, in turn suggesting that improvements in travel conditions of public transport might be as important as investing in shorter travel times.

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Bouscasse, Hélène. "Essays on travel mode choice modeling : a discrete choice approach of the interactions between economic and behavioral theories." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE2106/document.

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Cette thèse a pour objectif d’incorporer des éléments de théories de psychologie et d’économie comportementale dans des modèles de choix discret afin d’améliorer la compréhension du choix modal réalisé à l’échelle régionale. Les estimations se basent sur une enquête de type choice experiment présentée en première partie. Une deuxième partie s’intéresse à l’incorporation de variables latentes pour expliquer le choix modal. Après une revue de littérature sur les modèles de choix hybrides, c’est-à-dire des modèles combinant modèle d’équations structurelles et modèle de choix discret, un tel modèle est estimé pour montrer comment l’hétérogénéité d’outputs économiques (ici, la valeur du temps) peut être expliquée à l’aide de variables latentes (ici, le confort perçu dans les transports en commun) et de variables observables (ici, la garantie d’une place assise). La simulation de scénarios montre cependant que le gain économique (diminution de la valeur du temps) est plus élevé lorsque les politiques agissent sur des dimensions palpables que sur des dimensions latentes. S’appuyant sur un modèle de médiation, l’estimation d’un modèle d’équations structurelles montre par ailleurs que l’effet de la conscience environnementale sur les habitudes de choix modal est partiellement médié par l’utilité indirecte retirée de l’usage des transports en commun. Une troisième partie s’intéresse à deux formalisations de l’utilité issues de l’économie comportementale : 1) l’utilité dépendante au rang en situation de risque et 2) l’utilité dépendante à la référence. Dans un premier temps, un modèle d’utilité dépendante au rang est inséré dans des modèles de choix discret et, en particulier, un modèle à classes latentes, afin d’analyser l’hétérogénéité intra- et inter-individuelle lorsque le temps de déplacement n’est pas fiable. La probabilité de survenue d’un retard est sur-évaluée pour les déplacements en train et sous-évaluée pour les déplacements en voiture, en particulier pour les automobilistes, les usagers du train prenant d’avantage en compte l’espérance du temps de déplacement. Dans les modèles prenant en compte l’aversion au risque, les fonctions d’utilité sont convexes, ce qui implique une décroissance,de la valeur du temps. Dans un deuxième temps, une nouvelle famille de modèles de choix discret généralisant le modèle logit multinomial, les modèles de référence, est estimée. Sur mes données, ces modèles permettent une meilleure sélection des variables explicatives que le logit multinomial et l’estimation d’outputs économiques plus robustes, notamment en cas de forte hétérogénéité inobservée. La traduction économique des modèles de référence montre que les meilleurs modèles empiriques sont également les plus compatibles avec le modèle de dépendance à la référence de Tversky et Kahneman
The objective of this thesis is to incorporate aspects of psychology and behavioral economics theories in discrete choice models to promote a better understanding of mode choice at regional level. Part II examines the inclusion of latent variables to explain mode choice. A literature review of integrated choice and latent variable models – that is, models combining a structural equation model and a discrete choice model – is followed by the estimation of an integrated choice and latent variable model to show how the heterogeneity of economic outputs (here, value of time) can be explained with latent variables (here, perceived comfort in public transport) and observable variables (here, the guarantee of a seat). The simulation of scenarios shows, however, that the economic gain (decrease in value of time) is higher when policies address tangible factors than when they address latent factors. On the basis of a mediation model, the estimation of a structural equation model furthermore implies that the influence of environmental concern on mode choice habits is partially mediated by the indirect utility derived frompublic transport use. Part III examines two utility formulations taken from behavioral economics: 1) rankdependent utility to model risky choices, and 2) reference-dependent utility. Firstly, a rank-dependent utility model is included in discrete choice models and, in particular, a latent-class model, in order to analyze intra- and inter-individual heterogeneity when the travel time is subject to variability. The results show that the probability of a delay is over-estimated for train travel and under-estimated for car travel, especially for car users, as train users are more likely to take into account the expected travel time. In the models that account for risk aversion, the utility functions are convex, which implies a decrease in value of time. Secondly, a new family of discrete choice models generalizing the multinomial logit model, the reference models, is estimated. On my data, these models allow for a better selection of explanatory variables than the multinomial logit model and a more robust estimation of economic outputs, particularly in cases of high unobserved heterogeneity. The economic formulation of reference models shows thatthe best empirical models are also more compatible with Tversky et Kahneman’s reference-dependent model

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Robinson, Steve. "The development and application of an urban link travel time model using data derived from inductive loop detectors." Thesis, Imperial College London, 2007. http://hdl.handle.net/10044/1/1281.

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The need to measure urban link travel time (ULTT) is becoming increasingly important for the purposes both of network management and traveller information provision. This thesis develops a methodology by which data from single inductive loop detectors (ILDs) can be used to derive estimates of ULTT. Research is then undertaken to assess how effectively travel time data from this ULTT model can be used to model travel time variability (TTV). This research first looks at the issue of data quality. The Overtaking Rule method is developed to clean travel time data derived from ANPR cameras in London. A way of quantifying the effectiveness of ILD data cleaning treatments is proposed and the Daily Statistics Algorithm is identified as the best treatment. There are various limitations in existing ULTT models. To address these limitations, an alternative k nearest neighbors (k-NN) based method is proposed for use as a ULTT model. The key design parameters are identified and a 5-step process to optimise this model proposed. The k-NN method is found to outperform all other ULTT models on two links in central London. It is also found to be robust to changes in network characteristics and does not necessarily have to be optimised for each link. Data from the k-NN ULTT model allows various components of TTV to be modelled. In particular, it allows the true patterns of day-to-day variation to be identified. It also correctly models the distribution of travel time in approximately 50% of 15-minute time periods. As an application, the k-NN method could be used to aggregate GPS travel time records from different times but the same underlying travel time distribution together to enable more accurate estimates of ULTT.

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Holland, Richard John. "Real-time provision of local bus service information via the Internet : a comparative analysis using a fuzzy logic model of mode choice." Thesis, University of Newcastle Upon Tyne, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366577.

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Buczkowska, Sabina. "Quantitative models of establishments location choices : spatial effects and strategic interactions." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC0052/document.

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Dans un contexte de carence méthodologique, cette thèse vise à apporter un nouveau souffle aux modèles de choix de localisation jusqu’ici incapables d’appréhender de manière réaliste la complexité des processus décisionnels des établissements tels que leurs choix de localisation optimale. Les modèles de choix de localisation utilisent des données géoréférencées, pour lesquelles les ensembles de choix ont une composante spatiale explicite. Il est donc essentiel de comprendre comment représenter l’aspect spatial dans les modèles de choix de localisation. La décision finale d’un établissement semble être liée au paysage économique environnant. La quantification du lien entre les observations voisines implique une prise de décision sur la spécification de la matrice spatiale. Pourtant, la grande majorité des chercheurs appliquent la métrique euclidienne sans considérer des hypothèses sous-jacentes et ses alternatives. Cette démarche a été initialement proposée en raison de données et de puissance informatique limitées plutôt que de son universalité. Dans les régions comme la région parisienne, oû la congestion ainsi que les problèmes de barrières physiques non traversables apparaissent clairement, les distances purement basées sur la topographie peuvent ne pas être les plus appropriées pour l’étude de la localisation intra-urbaine. Il est possible d’acquérir des connaissances en reconsidérant et en mesurant la distance en fonction du problème analysé. Plutôt que d’enfermer les chercheurs dans une structure restrictive de la matrice de pondération, cette thèse propose une approche souple pour identifier la métrique de distance la plus susceptible de prendre en compte correctement les marchés voisins selon le secteur considéré. En plus de la distance euclidienne standard, six autres mesures sont testées : les temps de déplacement en voiture (pour les périodes de pointe et hors pointe) et en transport en commun, ainsi que les distances de réseau correspondantes.Par ailleurs, les décisions d’un établissement particulier sont interdépendantes des choix d’autres acteurs, ce qui rend les choix de localisation particulièrement intéressants et difficiles à analyser. Ces problèmes épineux posés par l’interdépendance des décisions ne peuvent généralement être négligés sans altérer l’authenticité du modèle de décision d’établissement. Les approches classiques de la sélection de localisation échouent en ne fournissant qu’un ensemble d’étapes systématiques pour la résolution de problèmes sans tenir compte des interactions stratégiques entre les établissements sur le marché. L’un des objectifs de la présente thèse est d’explorer comment adapter correctement les modèles de choix de localisation pour étudier les choix discrets d’établissement lorsqu’ils sont interdépendants.En outre, une entreprise peut ouvrir un certain nombre d’unités et servir le marché à partir de plusieurs localisations. Encore une fois, la théorie et les méthodes traditionnelles peuvent ne pas convenir aux situations dans lesquelles les établissements individuels, au lieu de se situer indépendamment les uns des autres, forment une grande organisation, telle qu’une chaîne confrontée à une concurrence féroce d’autres chaînes. Le modèle prend en compte non seulement les interactions intra-chaînes mais aussi inter-chaînes. Aussi, la nécessité d’indiquer une nette différence entre la population de jour et de nuit a été soulignée. La demande est représentée par les flux de piétons et de voitures, la foule de clients potentiels passant par les centres commerciaux, les stations de trains et de métros, les aéroports et les sites touristiques. L’Enquête Globale Transport 2010 (EGT 2010), entre autres, est utile pour atteindre cet objectif
This thesis is breathing new life into the location choice models of establishments. The need for methodological advances in order to more realistically model the complexity of establishment decision-making processes, such as their optimal location choices, is the key motivation of this thesis. First, location choice models use geo-referenced data, for which choice sets have an explicit spatial component. It is thus critical to understand how to represent spatial aspect in location choice models. The final decision of an establishment seems to be related to the surrounding economic landscape. When accounting for the linkage between neighboring observations, the decision on the spatial weight matrix specification must be made. Yet, researchers overwhelmingly apply the Euclidean metric without realizing its underlying assumptions and its alternatives. This representation has been originally proposed due to scarce data and low computing power, rather than because of its universality. In areas, such as the Paris region, where high congestion or uncrossable physical barriers problems clearly arise, distances purely based on topography may not be the most appropriate for the study of intra-urban location. There are insights to be gained by mindfully reconsidering and measuring distance depending on a problem being analyzed. Rather than locking researchers into a restrictive structure of the weight matrix, this thesis proposes a flexible approach to intimate which distance metric is more likely to correctly account for the nearby markets depending on the sector considered. In addition to the standard Euclidean distance, six alternative metrics are tested: travel times by car (for the peak and off-peak periods) and by public transit, and the corresponding network distances. Second, what makes these location choices particularly interesting and challenging to analyze is that decisions of a particular establishment are interrelated with choices of other players.These thorny problems posed by the interdependence of decisions generally cannot be assumed away, without altering the authenticity of the model of establishment decision making. The conventional approaches to location selection fail by providing only a set of systematic steps for problem-solving without considering strategic interactions between the establishments in the market. One of the goals of the present thesis is to explore how to correctly adapt location choice models to study establishment discrete choices when they are interrelated.Finally, a firm can open a number of units and serve the market from multiple locations. Once again, traditional theory and methods may not be suitable to situations wherein individual establishments, instead of locating independently from each other, form a large orgnization, such as a chain facing a fierce competition from other chains. There is a necessity to incorporate interactions between units within the same and competing firms. In addition, the need to state a clear difference between the daytime and nighttime population has been emphasized. Demand is represented by pedestrian and car flows, the crowd of potential clients passing through the commercial centers, train and subways stations, airports, and highly touristic sites. The Global Survey of Transport (EGT 2010), among others, is of service to reach this objective. More realistically designed location choice models accounting for spatial spillovers, strategic interaction, and with a more appropriate definition of distance and demand can become a powerful and flexible tool to assist in finding a befitting site. An appropriately chosen location in turn can make an implicative difference for the newly-created business. The contents of this thesis provide some useful recommendations for transport analysts, city planners, plan developers, business owners, and shopping center investors

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Perdomo, Jose Luis. "Detailed Haul Unit Performance Model." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/35012.

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In order to make a profit in any earthmoving operation it is important to plan the operation, select the appropriate equipment and use the haul units efficiently in order to obtain the maximum productivity. Maximizing productivity is one of construction project management personnel's primary objectives, but can also be one of their greatest challenges. The need for effective productivity planning is obvious since productivity ultimately translates into profit. In order to plan an earthmoving operation it is important to understand the travel times of the hauling equipment. Travel time is a variable that, in turn, depends upon other variables associated with the haul unit, and the haul road conditions. Presently there is no travel time model that appropriately considers these factors and simulates the interactions among them such that more detailed analysis could be performed. Such a model needs to be developed. The objective of this research is to develop a detailed model to simulate the travel time considering, in the amount of detail needed, the variables upon which travel time is dependent. The key in the development of the model is the calculation of acceleration. The simulation of how instantaneous acceleration varies may be a complex procedure because instantaneous acceleration is a function of numerous variables, many of which are in turn functions of the velocity and position, which are themselves integral functions of acceleration. The acceleration of a vehicle is dependent on the vehicle characteristics, road conditions, and operator. It is very difficult to consider changes in instantaneous acceleration by using analytical procedures. A numerical method should be used in order to analyze the complex system and determine the travel time or velocity profile of the vehicle. MATLAB software was used to analyze and solve the complex system numerically. A model that considers that the machine is working at full capacity was developed. It considers the variables that affect travel time in the amount of detail needed. The impact that the operator has in the machine performance can be highlighted after a comparison of the results obtained with actual field data, once the model is calibrated.
Master of Science

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Li, Ying. "Interest management scheme and prediction model in intelligent transportation systems." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45856.

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This thesis focuses on two important problems related to DDDAS: interest management (data distribution) and prediction models. In order to reduce communication overhead, we propose a new interest management mechanism for mobile peer-to-peer systems. This approach involves dividing the entire space into cells and using an efficient sorting algorithm to sort the regions in each cell. A mobile landmarking scheme is introduced to implement this sort-based scheme in mobile peer-to-peer systems. The design does not require a centralized server, but rather, every peer can become a mobile landmark node to take a server-like role to sort and match the regions. Experimental results show that the scheme has better computational efficiency for both static and dynamic matching. In order to improve communication efficiency, we present a travel time prediction model based on boosting, an important machine learning technique, and combine boosting and neural network models to increase prediction accuracy. We also explore the relationship between the accuracy of travel time prediction and the frequency of traffic data collection with the long term goal of minimizing bandwidth consumption. Several different sets of experiments are used to evaluate the effectiveness of this model. The results show that the boosting neural network model outperforms other predictors.

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Banerjee, Amlan. "Understanding activity engagement and time use patterns in a developing country context." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001729.

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Asenjo, Christian, Frank Tocas, Manuel Silvera, and Fernando Campos. "Analysis of the influence of the characteristics of the environment on the time of pedestrian transhipment in a multimodal transport using the social force model." Institute of Electrical and Electronics Engineers Inc, 2020. http://hdl.handle.net/10757/656408.

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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.
The Highway Capacity Manual (HCM-2010) indicates in Volume III (Chapter 17) how the characteristics of the environment can represent obstacles that influence the determination of the average pedestrian space. However, the HCM does not specifically analyse in detail how these obstacles affect specifically the path, speed and average walking time of pedestrian. This article performs a comparative analysis between two microsimulations models where it is evidence how by not considering the characteristics of the fixed and mobile environment, the transhipment time and the speed of people are modified. As a case study, the obstacles present in the environment during the transhipment carried out by users in an integrated multimodal transport system in the city of Lima are identified. The comparative analysis between both cases shows the influence of the characteristics of the environment of the transhipment and variation in the average speed of the pedestrians. The proposed study methodology is calibrated and validated by microsimulations in Vissim Software. The comparative analysis reflects an increase in the transhipment time of 19.4% and a decrease in the average speed of the pedestrians by 14.8 %, reflecting in the microsimulation model values near to the real behaviour of pedestrians.

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Falk, Helena. "Accessibility of Water Related, Cultural Ecosystem Services in Stockholm County." Thesis, KTH, Mark- och vattenteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-190700.

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The concept of ecosystem services is getting more used in planning. One important type of cultural ecosystem services is recreation, which has to be consumed where it is provided in contrast to services that can be transported to the beneficiaries. This creates a demand for users to move to the site of the service, making accessibility an important characteristic of the service. In a sustainable region the access to different services, including recreation, has to be considered in planning. With general transit feed specification data available, storing spatial information and time tables for public transport, the possibility to create time table dependent travel time models emerge. This study utilizes a prototype tool for a geographic information system software to create a network model using time tables to calculate travel times between different origins and water related, cultural ecosystem services via the public transport network in Stockholm County, Sweden. This allows for mapping of spatial variation of access within a region, and by combining this with current census data and population forecasts potential visitors to different recreational sites now and in the future can be estimated. By consulting regional planners in the design of the study the results were made useful for the study area Stockholm County as planning support system.

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Fan, Jingjing. "Operational evaluation of right turns followed by U-turns at signalized intersections as an alternative to direct left turns." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000431.

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Wilson, Douglas A. "An investigation into travel times and dispersion of pollution incidents into non-tidal river systems and the development of predictive network models." Thesis, University of Huddersfield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363236.

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González, Ramírez Humberto. "Study of the choice behaviour of travellers in a transport network via a “simulation game” Travel time and bounded rationality in travellers’ route choice behaviour : a computer route choice experiment Unravelling travellers’ route choice behaviour at full-scale urban network by focusing on representative OD pairs in computer experiments." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSET008.

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L'objectif de cette thèse est de trouver des modèles de choix d'itinéraire qui évoluent au niveau du réseau, c'est-à-dire des modèles qui rapprochent les choix des voyageurs sur la diversité des situations rencontrées dans un réseau de transport. L'approche de cette thèse pour étudier le comportement des voyageurs dans les réseaux de transport passe par des expériences informatiques à grande échelle, pour lesquelles une plateforme nommée Mobility Decision Game (MDG) a été développée. Le MDG permet d'observer les choix des participants sur un ensemble diversifié de scénarios (paires OD et itinéraires) avec des conditions de circulation et des informations de temps de trajet variables. Dans cette thèse, les expériences se concentrent sur les choix d'itinéraire des trajets en voiture qui sont basés sur la carte de la ville de Lyon, France. Pour atteindre l'objectif de cette thèse, une méthodologie de recherche de couples OD représentatifs du réseau est tout d'abord proposée. Les paires OD représentatives sont utilisées dans les expériences de choix de route pour obtenir des modèles de choix qui se généralisent aux différentes configurations OD dans le réseau. Deuxièmement, les choix des participants aux expériences sont analysés du point de vue du comportement rationnel et borné, afin d'établir le principe qui décrit le mieux leurs choix. Enfin, les modèles de choix sont évalués en fonction de leur précision prédictive. Cette thèse fait partie d'un projet européen ERC intitulé MAGnUM: Approche de modélisation du trafic multi-échelle et multimodale pour la gestion durable de la mobilité urbaine
The objective of this thesis is to find route choice models that scale-up at network level, i.e., models that predict the choices of travellers over the diversity of situations found in a transport network. The approach in this thesis to investigate travellers' behaviour in transportation networks is through computer-based experiments at large scale, for which a platform named the Mobility Decision Game (MDG), has been developed. The MDG permits to observe the choices of the participants on a diverse set of scenarios (OD pairs and routes) with varying traffic conditions and travel time information. In this thesis, the experiments focus on the route choices of uni-modal car trips that are based on the map of the city of Lyon, France. To attain the objective of this thesis, firstly a methodology to find OD pairs that are representative of the network is proposed. The representative OD pairs are used in route choice experiments to obtain choice models that generalise to the various OD configurations in the network. Secondly, the choices of participants in the experiments are analysed from the rational and boundedly rational behaviour perspectives, in order to establish the principle that best describe their choices. Finally, the choice models are assessed in terms of their predictive accuracy. This thesis is part of a European ERC project entitled MAGnUM: Multiscale and Multimodal Traffic Modeling Approach for Sustainable Management of Urban Mobility

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Lee, Sang Gu. "Integrating Data from Multiple Sources to Estimate Transit-Land Use Interactions and Time-Varying Transit Origin-Destination Demand." Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/265832.

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This research contributes to a very active body of literature on the application of Automated Data Collection Systems (ADCS) and openly shared data to public transportation planning. It also addresses the interaction between transit demand and land use patterns, a key component of generating time-varying origin-destination (O-D) matrices at a route level. An origin-destination (O-D) matrix describes the travel demand between two different locations and is indispensable information for most transportation applications, from strategic planning to traffic control and management. A transit passenger's O-D pair at the route level simply indicates the origin and destination stop along the considered route. Observing existing land use types (e.g., residential, commercial, institutional) within the catchment area of each stop can help in identifying existing transit demand at any given time or over time. The proposed research addresses incorporation of an alighting probability matrix (APM) - tabulating the probabilities that a passenger alights at stops downstream of the boarding at a specified stop - into a time-varying O-D estimation process, based on the passenger's trip purpose or activity locations represented by the interactions between transit demand and land use patterns. In order to examine these interactions, this research also uses a much larger dataset that has been automatically collected from various electronic technologies: Automated Fare Collection (AFC) systems and Automated Passenger Counter (APC) systems, in conjunction with other readily available data such as Google's General Transit Feed Specification (GTFS) and parcel-level land use data. The large and highly detailed datasets have the capability of rectifying limitations of manual data collection (e.g., on-board survey) as well as enhancing any existing decision-making tools. This research proposes use of Google's GTFS for a bus stop aggregation model (SAM) based on distance between individual stops, textual similarity, and common service areas. By measuring land use types within a specified service area based on SAM, this research helps in advancing our understanding of transit demand in the vicinity of bus stops. In addition, a systematic matching technique for aggregating stops (SAM) allows us to analyze the symmetry of boarding and alightings, which can observe a considerable passenger flow between specific time periods and symmetry by time period pairs (e.g., between AM and PM peaks) on an individual day. This research explores the potential generation of a time-varying O-D matrix from APC data, in conjunction with integrated land use and transportation models. This research aims at incorporating all valuable information - the time-varying alighting probability matrix (TAPM) that represents on-board passengers' trip purpose - into the O-D estimation process. A practical application is based on APC data on a specific transit route in the Minneapolis - St. Paul metropolitan area. This research can also provide other practical implications. It can help transit agencies and policy makers to develop decision-making tools to support transit planning, using improved databases with transit-related ADCS and parcel-level land use data. As a result, this work not only has direct implications for the design and operation of future urban public transport systems (e.g., more precise bus scheduling, improve service to public transport users), but also for urban planning (e.g., for transit oriented urban development) and travel forecasting.

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Schnapp, Allison M. "Estimating the Opportunity Cost of Time to Calculate the Willingness to Pay for Wetland Restoration at Maumee Bay State Park." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1302290962.

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Buonocore, Chiara. "Development of a model to choose the path of cyclists using GPS data collected via smartphone." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/17199/.

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Nowadays it is impossible being indifferent to the improvement of the urbanization and the mobility and sustainable road infrastructures.It has to be taken into account the bike as a mode of transport for many reasons such as:reduction of pollution and the emissions,safety on the road,less space and healthy.Mostly in big cities,perhaps it is the fastest mode of transport because it's not subject to traffic and its bottlenecks that block the flow.The Netherlands is the most interested country to travel by bike.It's the place where there are more bikes than cars.In recent years the availability of GPS data has seen a marked improvement in terms of accuracy,continuity and quality of data,thanks to the spread of smartphones and applications for auto-location and navigation.The main advantage is to obtain information on the travel routes actually followed by a large sample of cyclists on the entire network, from their origin to their destination.When GPS tracks can be attributed to detailed transport networks, it is possible to evaluate the factors that users consider in the process of choosing a specific route.It's important to study the choice of the route that cyclists make for many reasons.The objective of this thesis is to examine the aspects that the cyclists taking into account when they choose a route instead of another one.We want to focus on the time travelled,considering the average speed per each link and its correspondent length,and the average waiting times at the intersections:how the time influences cyclists choice. This research will investigate which aspects of the bicycle infrastructures have greater or lesser repercussions on the path made by the cyclists and to model their route choices.It will explore the link between the routes chosen by the cyclists and some attributes of the transport network of the Netherlands.The chosen routes will be compare with the fastest and the shortest calculated thanks to the network analyst in ArcMap for each OD pair.

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Westman, Freddie. "Modeller för restidsuppskattning baserat på Floating Car Data." Thesis, Linköping University, Department of Science and Technology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1510.

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I storstadsregionerna blir trafikläget allt mer ansträngt för vart år som går. Inflyttningen fortsätter i oförändrad takt och fler människor måste försöka samsas om samma utrymme. Situationen på vägarna börjar bli ohållbar och det måste till att dessa problem löses snart för att utvecklingen i regionerna inte ska stagnera. Möjligheter för ytterligare utbyignationer finns dock i en begränsad grad och man måste börja se till andra lösningar. Inom området för intelligenta transportsystem(ITS) erbjuds många nya tillämpningar där man med ny teknik försöker hitta lösningar till dagens trafikproblem. Ett led i detta är att samla in och distribuera information om restider på vägarna, för att försöka fördela trafiken mer jämt över hela vägnätet. Det finns olika metoder för att hämta in den här typen av information, men den här rapporten fokuserar sig vid att beskriva system baserat på Floating Car Data(FCD).

Arbetet som beskrivs i rapporten har i huvudsak analyserat fyra olika restidsuppskattnings-modeller och jämfört dessa med varandra. Modellerna baserar sina beräkningar på observationer från oidentifierade fordon, dvs att observationerna inte har någon identitetsstämpel som kan kopplas till ett specifikt fordon. Två av modellerna betraktar länkarna som en helhet och utför beräkningarna med detta som grund, medan de två andra delar upp varje länk i mindre segment vilket skapar möjlighet för en större noggrannhet. Modellerna testades inledningsvis på simulerad data baserat på trafikmätningar i Göteborgstrakten. Alla beräkningar begränsades ner till länknivå och inte hela vägnät. Detta p.g.a. att det initialt var för komplicerat att skapa en map- matchingmetod som skulle krävas för genomföra beräkningar på olika länkar samtidigt.

Efter genomförda tester på simulerad data prövades modellerna även på en reella datamängd hämtad från projektet Probe i Stockholmsområdet. Resultaten från de utförda testerna visar på att det inte skiljer sig nämnvärt i restidsuppskattningarna mellan de olika modellerna. Sträckan som valdes att analyseras i de simulerade fallen, påverkades inte av några större störningar eller flödesvariationer. Det resulterade i att alla modellerna genererade likvärdiga restider. Även i fallet med den reella datamängden, som innehöll större flödesvariationer över tiden, kunde de olika modellernas uppskattningar inte skiljas åt nämnvärt.

Slutsatsen är att trafiken i allmänhet inte har så kraftiga förändringar i flödet över tiden, att det krävs särskilt avancerade modeller för att beräkna restider på länknivå. I alla fall inte om man bortser från incidenter. De framräknade restiderna och den information som dessa ger, bör främst användas för direkt trafikstyrning för att uppnå önskat resultat. Människor förlitar sig mer till sina egna erfarenheter i kända områden, så information av den här typen lämpar sig mer som hjälpmedel för den enskilde individen vid resor i okänd trafik.

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Wan, Ke. "Estimation of Travel Time Distribution and Travel Time Derivatives." Thesis, Princeton University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3642164.

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Given the complexity of transportation systems, generating optimal routing decisions is a critical issue. This thesis focuses on how routing decisions can be computed by considering the distribution of travel time and associated risks. More specifically, the routing decision process is modeled in a way that explicitly considers the dependence between the travel times of different links and the risks associated with the volatility of travel time. Furthermore, the computation of this volatility allows for the development of the travel time derivative, which is a financial derivative based on travel time. It serves as a value or congestion pricing scheme based not only on the level of congestion but also its uncertainties. In addition to the introduction (Chapter 1), the literature review (Chapter 2), and the conclusion (Chapter 6), the thesis consists of two major parts:

In part one (Chapters 3 and 4), the travel time distribution for transportation links and paths, conditioned on the latest observations, is estimated to enable routing decisions based on risk. Chapter 3 sets up the basic decision framework by modeling the dependent structure between the travel time distributions for nearby links using the copula method. In Chapter 4, the framework is generalized to estimate the travel time distribution for a given path using Gaussian copula mixture models (GCMM). To explore the data from fundamental traffic conditions, a scenario-based GCMM is studied. A distribution of the path scenario representing path traffic status is first defined; then, the dependent structure between constructing links in the path is modeled as a Gaussian copula for each path scenario and the scenario-wise path travel time distribution is obtained based on this copula. The final estimates are calculated by integrating the scenario-wise path travel time distributions over the distribution of the path scenario. In a discrete setting, it is a weighted sum of these conditional travel time distributions. Different estimation methods are employed based on whether or not the path scenarios are observable: An explicit two-step maximum likelihood method is used for the GCMM based on observable path scenarios; for GCMM based on unobservable path scenarios, extended Expectation Maximum algorithms are designed to estimate the model parameters, which introduces innovative copula-based machine learning methods.

In part two (Chapter 5), travel time derivatives are introduced as financial derivatives based on road travel times—a non-tradable underlying asset. This is proposed as a more fundamental approach to value pricing. The chapter addresses (a) the motivation for introducing such derivatives (that is, the demand for hedging), (b) the potential market, and (c) the product design and pricing schemes. Pricing schemes are designed based on the travel time data captured by real time sensors, which are modeled as Ornstein-Uhlenbeck processes and more generally, continuous time auto regression moving average (CARMA) models. The risk neutral pricing principle is used to generate the derivative price, with reasonably designed procedures to identify the market value of risk.

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Hites, Gisèle. "Essays on the dynamics of cross-country income distribution and intra-household time allocation." Doctoral thesis, Universite Libre de Bruxelles, 2007. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210601.

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This thesis contributes to two completely unrelated debates in the economic literature, similar only in the relatively high degree of controversy characterizing each one.

The first part is methodological and macroeconomic in nature, addressing the question of whether the distribution of income across countries is converging (i.e. are the poor catching up to the rich?) or diverging (i.e. are we witnessing the formation of two exclusive clubs, one for poor countries and another one for rich countries?). Applications of the simple Markov model to this question have generated evidence in favor of the divergence hypothesis. In the first chapter, I critically review these results. I use statistical inference to show that the divergence results are not statistically robust, and I explain that this instability of the results comes from the application of a model for discrete data to data that is actually continuous. In the second chapter, I reposition the whole convergence-divergence debate by placing it in the context of Silverman’s classic survey of non-parametric density estimation techniques. This allows me to use the basic notions of fuzzy logic to adapt the simple Markov chain model to continuous data. When I apply the newly adapted Markov chain model to the cross-country distribution question, I find evidence against the divergence hypothesis, and this evidence is statistically robust.

The second part of the thesis is empirical and microeconomic in nature. I question whether observed differences between husbands’ and wives’ participation in labor markets are due to different preferences or to different constraints. My identification strategy is based on the idea that the more power an individual has relative to his/her partner, the more his/her actions will reflect his/her preferences. I use 2001 PSID data on cohabiting couples to estimate a simultaneous equations model of the spousal time allocation decision. My results confirm the stylized fact that specialization and trade does not explain time allocation for couples in which the wife is the primary breadwinner, and suggest that power could provide a more general explanation of the observations. My results show that wives with relatively more power choose to work more on the labor market and less at home, whereas husbands with more power choose to do the opposite. Since women start out from a lower level of labor market participation than men do, it would seem that spouses’ agree that the ideal mix of market work and housework lies somewhere between the husbands’ and the wives’ current positions.
Doctorat en sciences économiques, Orientation économie
info:eu-repo/semantics/nonPublished

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Pourfarzad, Amir. "On transport mode choice in natural disasters : A case study of the 2011 Brisbane floods." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/98001/1/Amir_Pourfarzad_Thesis.pdf.

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This project was a step forward in developing the scientific basis for a method to investigate mode choice/change in natural disasters using the 2011 Brisbane floods as a case study. Statistical models were developed on characteristics affecting traveller’s behavioural changes in times of natural disasters. Understating travellers' modal change is key when identifying methods to efficiently and effectively manage transport networks in times of disaster, specially during a flood event. The proposed framework adopted within this research represents a significant innovation and contribution to knowledge to subject of transport mode choice during disasters and lay ground work for future policy focused studies.

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Liu, Yulin. "Urban transit quality of service : user perception and behaviour." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/61517/1/Yulin_Liu_Thesis.pdf.

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Despite its potential multiple contributions to sustainable policy objectives, urban transit is generally not widely used by the public in terms of its market share compared to that of automobiles, particularly in affluent societies with low-density urban forms like Australia. Transit service providers need to attract more people to transit by improving transit quality of service. The key to cost-effective transit service improvements lies in accurate evaluation of policy proposals by taking into account their impacts on transit users. If transit providers knew what is more or less important to their customers, they could focus their efforts on optimising customer-oriented service. Policy interventions could also be specified to influence transit users’ travel decisions, with targets of customer satisfaction and broader community welfare. This significance motivates the research into the relationship between urban transit quality of service and its user perception as well as behaviour. This research focused on two dimensions of transit user’s travel behaviour: route choice and access arrival time choice. The study area chosen was a busy urban transit corridor linking Brisbane central business district (CBD) and the St. Lucia campus of The University of Queensland (UQ). This multi-system corridor provided a ‘natural experiment’ for transit users between the CBD and UQ, as they can choose between busway 109 (with grade-separate exclusive right-of-way), ordinary on-street bus 412, and linear fast ferry CityCat on the Brisbane River. The population of interest was set as the attendees to UQ, who travelled from the CBD or from a suburb via the CBD. Two waves of internet-based self-completion questionnaire surveys were conducted to collect data on sampled passengers’ perception of transit service quality and behaviour of using public transit in the study area. The first wave survey is to collect behaviour and attitude data on respondents’ daily transit usage and their direct rating of importance on factors of route-level transit quality of service. A series of statistical analyses is conducted to examine the relationships between transit users’ travel and personal characteristics and their transit usage characteristics. A factor-cluster segmentation procedure is applied to respodents’ importance ratings on service quality variables regarding transit route preference to explore users’ various perspectives to transit quality of service. Based on the perceptions of service quality collected from the second wave survey, a series of quality criteria of the transit routes under study was quantitatively measured, particularly, the travel time reliability in terms of schedule adherence. It was proved that mixed traffic conditions and peak-period effects can affect transit service reliability. Multinomial logit models of transit user’s route choice were estimated using route-level service quality perceptions collected in the second wave survey. Relative importance of service quality factors were derived from choice model’s significant parameter estimates, such as access and egress times, seat availability, and busway system. Interpretations of the parameter estimates were conducted, particularly the equivalent in-vehicle time of access and egress times, and busway in-vehicle time. Market segmentation by trip origin was applied to investigate the difference in magnitude between the parameter estimates of access and egress times. The significant costs of transfer in transit trips were highlighted. These importance ratios were applied back to quality perceptions collected as RP data to compare the satisfaction levels between the service attributes and to generate an action relevance matrix to prioritise attributes for quality improvement. An empirical study on the relationship between average passenger waiting time and transit service characteristics was performed using the service quality perceived. Passenger arrivals for services with long headways (over 15 minutes) were found to be obviously coordinated with scheduled departure times of transit vehicles in order to reduce waiting time. This drove further investigations and modelling innovations in passenger’ access arrival time choice and its relationships with transit service characteristics and average passenger waiting time. Specifically, original contributions were made in formulation of expected waiting time, analysis of the risk-aversion attitude to missing desired service run in the passengers’ access time arrivals’ choice, and extensions of the utility function specification for modelling passenger access arrival distribution, by using complicated expected utility forms and non-linear probability weighting to explicitly accommodate the risk of missing an intended service and passenger’s risk-aversion attitude. Discussions on this research’s contributions to knowledge, its limitations, and recommendations for future research are provided at the concluding section of this thesis.

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Nutakor, Christopher K. "Urban travel time models : Vancouver (BC) case study." Thesis, 1992. http://hdl.handle.net/2429/3373.

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Travel time survey data obtained from the City of Vancouver’s Engineering Department have revealed that, travel times in the City of Vancouver have remained fairly constant over the past three decades, although traffic volumes and the number of traffic control devices have increased. This pattern of travel times is contrary to the predicted travel time behaviour of traditional travel time models, The traditional travel time models generally predict travel time as increasing with increasing traffic volume. This thesis investigated the reasons for the observed travel time trends. It also investigated the validity of three traditional time models, using data collected on a few arterial streets in the City of Vancouver. The results from the research indicated that, the observed travel time trends are principally due to increases in vehicle speeds and increases in the capacity of the street network. The three traditional travel time models which were investigated for validity are the BPR model, the GVRD model and the Davidson model. None of the three models investigated provided a good fit for data collected on the arterial streets. Based on the data collected on one of the arterials, revised forms of the models were developed. The revised models were validated against data collected on three other arterials in the City of Vancouver. In all cases, the validation process proved satisfactory.

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Micklethwait, Guy Roland. "Models of Time Travel: a comparative study using films." Phd thesis, 2012. http://hdl.handle.net/1885/9486.

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This research identifies the way the science of time travel is presented to the public through the medium of feature films, and discovers if this can be used to construct a comprehensive set of models about time travel and its consequences. There is no universally accepted understanding of what constitutes the nature of time. Even though the fundamental laws of physics do not prohibit time travel, scientists and philosophers do not agree about what would happen if backwards time travel ever became a reality. I identified models that scientists and philosophers have produced about the nature of time, time travel and other temporal phenomena. I then determined the model of time used in each of the 100 time travel films that I reviewed. I also used a verbal survey to elicit the personal models of time travel for each participant of three focus groups I conducted with members of the movie-going public. I compared these models of time with the personal models used by members of the movie-going public and synthesised them to develop a comprehensive set of 21 models of time. The "guyline" diagrams that I devised proved to be a very useful tool for analysing how the timelines of the time travellers behaved in each film. My research has shown that an investigation of time travel in films can indeed be used to construct useful models of time based on the evidence of the 21 models that I developed. Furthermore, I showed that both my models of time travel and my guyline diagrams helped to structure conversations about time with members of the movie-going public. The findings of this thesis can be used by scientists, philosophers, filmmakers and the public to help them clarify our thinking about time travel, the nature of time, how it is communicated, and also in future research.

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Dissertations / Theses on the topic 'Models of time travel'

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