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1
Lu, Chenxi. "Improving Analytical Travel Time Estimation for Transportation Planning Models." FIU Digital Commons, 2010. http://digitalcommons.fiu.edu/etd/237.
Повний текст джерелаАнотація:
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.
2
Henclewood, Dwayne Anthony. "Real-time estimation of arterial performance measures using a data-driven microscopic traffic simulation technique." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/44792.
Повний текст джерелаАнотація:
Traffic congestion is a one hundred billion dollar problem in the US. The cost of congestion has been trending upward over the last few decades, but has experienced slight decreases in recent years partly due to the impact of congestion reduction strategies. The impact of these strategies is however largely experienced on freeways and not arterials. This discrepancy in impact is partially linked to the lack of real-time, arterial traffic information. Toward this end, this research effort seeks to address the lack of arterial traffic information.
To address this dearth of information, this effort developed a methodology to provide accurate estimates of arterial performance measures to transportation facility managers and travelers in real-time. This methodology employs transmitted point sensor data to drive an online, microscopic traffic simulation model. The feasibility of this methodology was examined through a series of experiments that were built upon the successes of the previous, while addressing the necessary limitations. The results from each experiment were encouraging. They successfully demonstrated the method's likely feasibility, and the accuracy with which field estimates of performance measures may be obtained. In addition, the method's results support the viability of a "real-world" implementation of the method. An advanced calibration process was also developed as a means of improving the method's accuracy. This process will in turn serve to inform future calibration efforts as the need for more robust and accurate traffic simulation models are needed.
The success of this method provides a template for real-time traffic simulation modeling which is capable of adequately addressing the lack of available arterial traffic information. In providing such information, it is hoped that transportation facility managers and travelers will make more informed decisions regarding more efficient management and usage of the nation's transportation network.
3
Hodges, Fiona. "Travel time budgets in an urban area /." Connect to thesis, 1994. http://eprints.unimelb.edu.au/archive/00000227.
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4
Chan, Ping-ching Winnie. "The value of travel time savings in Hong Kong." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk:8888/cgi-bin/hkuto%5Ftoc%5Fpdf?B23425003.
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5
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.
Повний текст джерелаАнотація:
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.
6
Misra, Rajul. "Toward a comprehensive representation and analysis framework for non-worker activity-travel pattern modeling /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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7
Li, Lok-man Jennifer. "Schedule delay of work trips in Hong Kong an empirical analysis /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B40988041.
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8
Choy, Wing-pong. "A review of the value of travel time in Hong Kong." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B31937068.
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Chan, Ping-ching Winnie, and 陳冰淸. "The value of travel time savings in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31954789.
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10
Adams, David Lewis. "Integrating travel time reliability into management of highways." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 52 p, 2008. http://proquest.umi.com/pqdweb?did=1459913561&sid=3&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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11
Glick, Travis Bradley. "Utilizing High-Resolution Archived Transit Data to Study Before-and-After Travel-Speed and Travel-Time Conditions." PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/4065.
Повний текст джерелаАнотація:
Travel times, operating speeds, and service reliability influence costs and service attractiveness. This paper outlines an approach to quantify how these metrics change after a modification of roadway design or transit routes using archived transit data. The Tri-County Metropolitan Transportation District of Oregon (TriMet), Portland's public transportation provider, archives automatic vehicle location (AVL) data for all buses as part of their bus dispatch system (BDS). This research combines three types of AVL data (stop event, stop disturbance, and high-resolution) to create a detailed account of transit behavior; this probe data gives insights into the behavior of transit as well as general traffic. The methodology also includes an updated approach for confidence intervals estimates that more accurately represent of range of speed and travel time percentile estimates. This methodology is applied to three test cases using a month of AVL data collected before and after the implementation of each roadway change. The results of the test cases highlight the broad applicability for this approach to before-and-after studies.
12
Choy, Wing-pong, and 蔡榮邦. "A review of the value of travel time in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B31937068.
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13
Molla, Mohammad Mofigul Islam. "A Stochastic Bayesian Update and Logistic Growth Mapping of Travel-Time Flow Relationship." Diss., North Dakota State University, 2017. http://hdl.handle.net/10365/25911.
Повний текст джерелаАнотація:
The travel-time flow relationship is not always increasing in nature, it is very difficult to predict precisely. Traditional method fails to replicate this unique conditions. Until millennium, although various researchers and practitioners have given much attention to develop travel-time flow relationships, the advancement to improve travel-time flow relationships was not substantial. The knowledge about the travel-time flow relationship is not commensurate with or parallel to the advancement of new knowledge in other fields. After millennium, most investigators did not devote enough attention to create new knowledge, except for application and performance evaluation of the existing knowledge. Therefore, it is necessary to provide a new theoretical and methodological advancement in travel-time flow relationship.
Consequentially, this research proposes a new methodology, which considers stochastic behavior of travel-time flow relationship with probabilistic Bayesian statistics and logistic growth mapping techniques. This research moderately improves the travel-time flow relationship. The unique contribution of this research is that the proposed methods outperforms the existing traditional travel-time flow theory, assumptions, and modeling techniques. The results shows that the proposed model is considerably a good candidate for travel-time predictions. The proposed model performs 36 percent better and accurate travel-time predictions in compared to the existing models.
Furthermore, travel-time flow relationship need capacity and free-flow speed estimations. Traditionally, practice of capacity estimation is mostly practical, subjective, and not steady-state capacity. Therefore, a robust and stable capacity-estimation method was developed to eliminate the subjectivity of capacity estimation. The proposed model shows robust and capable of replicating steady-state capacity estimation. The free-flow speed estimation should relate to the traffic-flow speed model while the density is zero. Therefore, this research investigates the existing deterministic speed-density models and recommends a better methodology in free-flow speed estimation. This research presents how the undefined practice of free-flow speed selection can be sensitive.
Additionally, finding suitable concurrent travel-time data and traffic volume is crucial and very challenging. To collect concurrent data, this research investigates and develops several technologies such as crowdsource, web app, virtual sensor method, test vehicle, smartphone, global positioning system, and utilized several state and local agencies data collection efforts.
Keywords: Travel-Time Flow, Travel-Time Delay, Volume-Delay Function, Travel Time, Origin-Destination Survey, Travel Demand Model, Travel Data Collection, Transportation Survey, Internet Sensor, Crowdsourcing, Virtual Sensor Method, VSM, Transportation Planning, GPS, Smartphone, Loop Detector, Travel -Time Prediction, Travel-Speed Prediction, TDM, Bayesian Inference, Logistic Growth Function.
14
Washburn, Scott Stuart. "New technologies for data collection and their application for empirical investigation of travel time measurement issues /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/10139.
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Zhu, Yi. "Mixed traffic in Chinese cities : bicycle and the intersection problems." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0019/MQ54315.pdf.
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16
Zhang, Xu. "INCORPORATING TRAVEL TIME RELIABILITY INTO TRANSPORTATION NETWORK MODELING." UKnowledge, 2017. http://uknowledge.uky.edu/ce_etds/54.
Повний текст джерелаАнотація:
Travel time reliability is deemed as one of the most important factors affecting travelers’ route choice decisions. However, existing practices mostly consider average travel time only. This dissertation establishes a methodology framework to overcome such limitation.
Semi-standard deviation is first proposed as the measure of reliability to quantify the risk under uncertain conditions on the network. This measure only accounts for travel times that exceed certain pre-specified benchmark, which offers a better behavioral interpretation and theoretical foundation than some currently used measures such as standard deviation and the probability of on-time arrival.
Two path finding models are then developed by integrating both average travel time and semi-standard deviation. The single objective model tries to minimize the weighted sum of average travel time and semi-standard deviation, while the multi-objective model treats them as separate objectives and seeks to minimize them simultaneously. The multi-objective formulation is preferred to the single objective model, because it eliminates the need for prior knowledge of reliability ratios. It offers an additional benefit of providing multiple attractive paths for traveler’s further decision making.
The sampling based approach using archived travel time data is applied to derive the path semi-standard deviation. The approach provides a nice workaround to the problem that there is no exact solution to analytically derive the measure. Through this process, the correlation structure can be implicitly accounted for while simultaneously avoiding the complicated link travel time distribution fitting and convolution process.
Furthermore, the metaheuristic algorithm and stochastic dominance based approach are adapted to solve the proposed models. Both approaches address the issue where classical shortest path algorithms are not applicable due to non-additive semi-standard deviation. However, the stochastic dominance based approach is preferred because it is more computationally efficient and can always find the true optimal paths.
In addition to semi-standard deviation, on-time arrival probability and scheduling delay measures are also investigated. Although these three measures share similar mathematical structures, they exhibit different behaviors in response to large deviations from the pre-specified travel time benchmark. Theoretical connections between these measures and the first three stochastic dominance rules are also established. This enables us to incorporate on-time arrival probability and scheduling delay measures into the methodology framework as well.
17
Key, Justin. "Real-Time Open Source Traffic Control Software for the Advance Traffic Controller." Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5377.
Повний текст джерелаАнотація:
Under the initiative of Department of Transportation (DOT) a safety-critical, dual redundant, open source traffic signal control application is currently being developed. The system named SCOPE, for Signal Control Program Environment, currently implements standard 8-phase NEMA logic and the National Cooperative Highway Research Program 3-66 preemption logic. SCOPE is designed to be part of the Advanced Traffic Controller (ATC), making use of API standard 2.06b to integrate with the hardware. Safety-critical status is achieved through redundancy of application logic that constantly compares expected signal phase information. From baseline requirements, engineers independently program application code, one using Ada95 and the other using C++. The Traffic EXperimental Analytical Simulation Model, a microscopic single-intersection vehicular simulation, was used for initial validation and testing of the functionality of the system. The second demonstration of the SCOPE, used actuated detector data collected from a recording of a live intersection. Actuator calls were placed on SCOPE at the same times the vehicles triggered the detectors in the video (assuming the vehicles were not in-queue). Using SCOPE the real-world traffic was not only right-of-way safely yielded, but the traffic flow state time average time in-queue reduced. The final phase of testing will occur when the DOT performs Formal Qualification Testing, which is scheduled for 2013. Upon validation and subsequent release to the open source community SCOPE will provide users the ability to replace the proprietary application software residing in ATC cabinets. Transparency will be provided into another aspect of the traffic control signal thus taking the initiative of ATC one step further.Ph.D.
Doctorate
Industrial Engineering and Management Systems
Engineering and Computer Science
Modeling and Simulation; Engineering
18
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.
Повний текст джерелаАнотація:
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.
19
Elsayed, Mohamed, and Erik Torstensson. "Two different bus stop layout designs : A traffic simulation study in Vissim." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-170877.
Повний текст джерелаАнотація:
Bicycles are one of the most efficient way to travel within short-distance trips due to its relatively low maintenance and operation costs (Gao, Liu, & Feng, 2012). Besides to their efficiency, bicycles provide more flexibility for their parking and its ease of use. With the increasing transportation demand in major cities, transportation authorities will encourage to use the bicycle more. However, accommodating bicycles would require physical road geometry modifications such as introducing dedicated bicycle-lanes. Cycling appears to be a sustainable form of transportation across virous countries in Europe, as a result the authorities are planning and implementing upgrades to make the transportation system safer, convenient and sustainable which is necessary to encourage more people to use bicycles as a form of transportation. This thesis is a case study which examines current traffic conditions on a bus stop at Långholmsgatan in the city of Stockholm, Sweden and evaluates the effects of different designs for bicycles and buses. At this bus stop in Långholmsgatan, the bicycle lane is located to the right of the traffic road and to the left of the bus stop in the upstream direction. Buses need to cross the bicycle lane in order to arrive and departure the bus stop. Consequently, a conflict will also be created between bicycles and buses that are crossing the bicycle lane. In this thesis, an alternative design is evaluated in which buses and bicycles are separated from each other. However, this will result in a new conflict between bicycles and pedestrians. These two designs are evaluated in terms of travel time and delay and the analysis was done using micro-simulation software VISSIM. The study shows that the current design at the bus stop of Långholmsgatan should be preferred over the alternative design when considering travel time and delay for bicycles. If buses should be considered, the alternative design should be preferred over the current design.
20
Azimian, Amin. "Design of an Intelligent Traffic Management System." University of Dayton / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1323275800.
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21
Luo, Xiaowei. "Transport network with degradable links and stochastic demands /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202004%20LUO.
Повний текст джерелаАнотація:
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.Includes bibliographical references (leaves 62-64). Also available in electronic version. Access restricted to campus users.
22
Paz, Avila Luis Albert 1964. "Algorithm development for solving the emergency vehicle location problem with stochastic travel times and unequal vehicle utilizations." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276917.
Повний текст джерелаАнотація:
This thesis deals with the problem of locating emergency vehicles in an urban area. An optimization model is formulated that extends previous work by allowing stochastic travel times, unequal vehicle utilizations, and backup service. The heart of the model is a procedure similar to the Hypercube approximation model. Ten pair-wise interchange heuristics are developed and tested on 240 test problems. Demand and service time components of the test data have been generated using characteristics of the Tucson Emergency Medical System. Geographical components of the test data have been generated using actual city shapes as models. It is believed that these test problems are more indicative of actual emergency vehicle location problems than those previously presented in the literature.
23
Carbajo, Fuertes Eduardo. "Combination of travel time and delay measurements in an urban traffic controller : A case study of Zuidas." Thesis, KTH, Transportvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-222020.
Повний текст джерелаАнотація:
Increasing traffic volume in the urban areas is leading to a series of negative effects such as congestion or emission of air pollutants. The city of Amsterdam is no exception to this trend and a sustainable solution is sought in the area of Traffic Management and Intelligent Transportation Systems. The goal of this study is to develop a traffic management strategy that enhances the traffic performance in distributor roads (Plus Network Auto in Amsterdam) during saturated conditions (AM and PM peak). After the analysis of the current state of the traffic management in the municipality of Amsterdam, an opportunity has been detected in which a combination of the different systems in place can be used to improve the traffic performance of the local road network. Travel time and delay measurements retrieved from inductive-loop detectors, automatic number plate recognition cameras and floating car data are used in a top-level urban traffic controller that combines the traffic responsiveness of a vehicle-actuated controller with the effective coordination of a fixed-time controller. The proposed controller can act locally when the delay measurements show congestion at a single intersection or along the whole corridor when the average speed drops below a specified threshold. A microscopic simulation model of the Zuidas district for the year 2030 and the PM peak has been used to evaluate the proposed top-level controller compared to the currently used vehicle-actuated controller and the coordinated fixed-time controller. The results show that the average speed in the main corridor has been increased by 28,5% and meets the desired speed set by the municipality for the Plus Network Auto. Overall delays at the intersections are reduced in average by 11,60% while the effect on the public transport modes remains similar. However, the coordinated fixed-time controller has shown even a better performance than the proposed top-level controller, for which a series of recommendations have been issued.
24
Persson, Johan. "Improvement of Estimated Time of Arrival for Railroad Traffic." Thesis, Blekinge Tekniska Högskola, Avdelningen för programvarusystem, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-1653.
Повний текст джерелаАнотація:
Denna rapporten studerar effekterna i det svenska järnvägsnätet och kvaliten på de estimerade ankomsttider för tågen. Effekterna som studeras i rapporten är resultatet av hur kvaliten på ankomsttideren ändras när en positioneringsapparat introduceras i järnvägstrafiken. Rapporten studerar också hur kvaliten på uppskattningen av ankomsttidernas ändras då man reducerar antalet driftledningscentraler och centraliserar järnvägsorganisationen. Rapporten fortsätter med att rangordna dessa olika metoder och utreda vilken av de två metoderna som har störst inverkan och som är den mest fördelaktiga metoden. Ett försök görs också att sätta ett värde på hur mycket bättre varje metod, och olika kombinationer av metoderna, är i förhållande till varandra.Denna rapporten studerar effekterna i det svenska järnvägsnätet och kvaliten på de estimerade ankomsttider för tågen. Effekterna som studeras i rapporten är resultatet av hur kvaliten på ankomsttideren ändras när en positioneringsapparat introduceras i järnvägstrafiken. Rapporten studerar också hur kvaliten på uppskattningen av ankomsttidernas ändras då man reducerar antalet driftledningscentraler och centraliserar järnvägsorganisationen. Rapporten fortsätter med att rangordna dessa olika metoder och utreda vilken av de två metoderna som har störst inverkan och som är den mest fördelaktiga metoden. Ett försök görs också att sätta ett värde på hur mycket bättre varje metod, och olika kombinationer av metoderna, är i förhållande till varandra.
Email: jo.persson@gmail.com
25
Wong, Yee-fang Eva. "A study of the transport needs of patients for medical services, with special emphasis on cost minimization." Click to view the E-thesis via HKUTO, 2002. http://sunzi.lib.hku.hk/hkuto/record/B42576313.
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26
Kaufmann, Ronald Douglas. "Joint inversion of travel-time residuals and gravity anomalies for the velocity structure of Southest Tennessee." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/25730.
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27
Zhang, Haizheng Ph D. Massachusetts Institute of Technology. "Online calibration for simulation-based dynamic traffic assignment : towards large-scale and real-time performance." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/120603.
Повний текст джерелаАнотація:
Thesis: Ph. D. in Transportation, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 149-152).
The severity of traffic congestion is increasing each year in the US, resulting in higher travel times, and increased energy consumption and emissions. They have led to an increasing emphasis on the development of tools for trac management, which intends to alleviate congestion by more eciently utilizing the existing infrastructure. Eective trac management necessitates the generation of accurate short-term predictions of trac states and in this context, simulation-based Dynamic Trac Assignment (DTA) systems have gained prominence over the years. However, a key challenge that remains to be addressed with real-time DTA systems is their scalability and accuracy for applications to large-scale urban networks. A key component of real-time DTA systems that impacts scalability and accuracy is online calibration which attempts to adjust simulation parameters in real-time to match as closely as possible simulated measurements with real-time surveillance data. This thesis contributes to the existing literature on online calibration of DTA systems in three respects: (1) modeling explicitly the stochasticity in simulators and thereby improving accuracy; (2) augmenting the State Space Model (SSM) to capture the delayed measurements on large-scale and congested networks; (3) presenting a gradient estimation procedure called partitioned simultaneous perturbation (PSP) that utilizes an assumed sparse gradient structure to facilitate real-time performance. The results demonstrate that, first, the proposed approach to address stochasticity improves the accuracy of supply calibration on a synthetic network. Second, the augmented SSM improves both estimation and prediction accuracy on a congested synthetic network and the large-scale Singapore expressway network. Finally, compared with the traditional finite difference method, the PSP reduces the number of computations by 90% and achieves the same calibration accuracy on the Singapore expressway network. The proposed methodologies have important applications in the deployment of real-time DTA systems for large scale urban networks.
by Haizheng Zhang.
Ph. D. in Transportation
28
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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Thornton, Douglas Anthony. "Investigation of using radar augmented transit buses as arterial travel time probes." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1243907350.
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Hadfield, Mitchell Gregory. "Analysis of Performance Measures of Traffic Incident Management in Utah." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8529.
Повний текст джерелаАнотація:
In 2009 the Federal Highway Administration published a report regarding a Focus States Initiative that had been conducted with 11 states to discuss the development of national Traffic Incident Management (TIM) standards. Performance measures were defined, and a national TIM dashboard created, but very little data has been added to the dashboard since. In this research study, performance measures of the Utah Department of Transportation (UDOT) TIM program were analyzed. Data availability was first assessed to determine whether these performance measures could be calculated. It was determined that crash response data available from the Utah Highway Patrol (UHP) could be used to calculate the performance measures of Incident Management Teams (IMT) and UHP units; however, roadway clearance data were missing. UHP personnel agreed to collect additional data regarding crash roadway clearance for six months of the study. Performance measures of response time (RT), roadway clearance time (RCT), and incident clearance time (ICT) were calculated for responding units at 168 crashes. Using the crash response data from UHP and traffic speed, travel time, and volume data from UDOT databases, 83 of the 163 crashes that met additional criteria were evaluated to determine the volume of traffic affected (AV) by each incident and the associated user cost (EUC). Statistical analyses to determine relationships between different measures such as RT, RCT, ICT, AV, and EUC were conducted to assist UDOT in optimizing the allocation of their IMT resources.
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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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Feng, Wei. "Analyses of Bus Travel Time Reliability and Transit Signal Priority at the Stop-To-Stop Segment Level." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/1832.
Повний текст джерелаАнотація:
Transit travel time is affected by many factors including traffic signals and traffic condition. Transit agencies have implemented strategies such as transit signal priority (TSP) to reduce transit travel time and improve service reliability. However, due to the lack of empirical data, the joint impact of these factors and improvement strategies on bus travel time has not been studied at the stop-to-stop segment level.
This study utilizes and integrates three databases available along an urban arterial corridor in Portland, Oregon. Data sources include stop-level bus automatic vehicle location (AVL) and automatic passenger count (APC) data provided by the Tri-County Metropolitan Transportation District of Oregon (TriMet), the Sydney Coordinated Adaptive Traffic System (SCATS) signal phase log data, and intersection vehicle count data provided by the City of Portland. Based on the unique collection and integration of these fine granularity empirical data, this research utilizes multiple linear regression models to understand and quantify the joint impact of intersection signal delay, traffic conditions and bus stop location on bus travel time and its variability at stop-to-stop segments. Results indicate that intersection signal delay is the key factor that affects bus travel time variability. The amount of signal delay is nearly linearly associated with intersection red phase duration. Results show that the effect of traffic conditions (volumes) on bus travel time varies significantly by intersection and time of day.
This study also proposed new and useful performance measures for evaluating the effectiveness of TSP systems. Relationships between TSP requests (when buses are late) and TSP phases were studied by comparing TSP phase start and end times with bus arrival times at intersections. Results show that green extension phases were rarely used by buses that requested TSP and that most green extension phases were granted too late. Early green effectiveness (percent of effective early green phases) is much higher than green extension effectiveness. The estimated average bus and passenger time savings from an early green phase are also greater compared to the average time savings from a green extension phase. On average, the estimated delay for vehicles on the side street due to a TSP phase is less than the time saved for buses and automobiles on the major street.
Results from this study can be used to inform cities and transit agencies on how to improve transit operations. Developing appropriate strategies, such as adjusting bus stop consolidation near intersections and optimizing bus operating schedules according to intersection signal timing characteristics, can further reduce bus travel time delay and improve TSP effectiveness.
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Vo, Trung. "An investigation of bluetooth technology for measuring travel times on arterial roads: a case study on spring street." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39597.
Повний текст джерелаАнотація:
Research in the field of travel time measurement using Bluetooth technology has been an area of great interest in recent years as transportation professionals strive to increase the cost-effectiveness, accuracy, anonymity, and safety of travel time data collection methods. Commonly used travel time data collection methods include the use of inductive loops, video cameras, and probe vehicles. However, Bluetooth, a globally accepted wireless technology, serves as the medium being utilized by more and more transportation consultants, public agencies, and academics in the collection of travel time data. This study seeks to develop a methodology for measuring travel times on arterial roads using Bluetooth technology. A literature review of general travel time methods and Bluetooth travel time methods was conducted to provide the context for a Bluetooth field deployment development and implementation. The study presents the deployment plan and data analysis of a case study conducted on Spring Street in Atlanta, Georgia. Variable heights, Bluetooth to Bluetooth interference, and detection of Bluetooth devices in probe vehicles are investigated and recommendations are suggested for future Bluetooth travel time studies.
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Colberg, Kathryn. "Investigating the ability of automated license plate recognition camera systems to measure travel times in work zones." Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49048.
Повний текст джерелаАнотація:
This thesis evaluates the performance of a vehicle detection technology, Automated License Plate Recognition (ALPR) camera systems, with regards to its ability to produce real-time travel time information in active work zones. A literature review was conducted to investigate the ALPR technology as well as to identify other research that has been conducted using ALPR systems to collect travel time information. Next, the ALPR technology was tested in a series of field deployments in both an arterial and a freeway environment. The goal of the arterial field deployment was to evaluate the optimal ALPR camera angles that produce the highest license plate detection rates and accuracy percentages. Next, a series of freeway deployments were conducted on corridors of I-285 in Atlanta, Georgia in order to evaluate the ALPR system in active work zone environments. During the series of I-285 freeway deployments, ALPR data was collected in conjunction with data from Bluetooth and radar technologies, as well as from high definition video cameras. The data collected during the I-285 deployments was analyzed to determine the ALPR vehicle detection rates. Additionally, a script was written to match the ALPR reads across two data collection stations to determine the ALPR travel times through the corridors. The ALPR travel time data was compared with the travel time data produced by the Bluetooth and video cameras with a particular focus on identifying travel time biases associated with each given technology. Finally, based on the knowledge gained, recommendations for larger-scale ALPR work zone deployments as well as suggestions for future research are provided.
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Kristoffersson, Ida. "Incorporation of Departure Time Choice in a Mesoscopic Transportation Model for Stockholm." Licentiate thesis, Stockholm : Transport- och samhällsekonomi, Kungliga Tekniska högskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10516.
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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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Li, Ying. "Interest management scheme and prediction model in intelligent transportation systems." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45856.
Повний текст джерелаАнотація:
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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Twagirimana, Janvier. "Establishing and applying speed-flow relationships for traffic on rural two-lane two- way highways in the Western Cape." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85825.
Повний текст джерелаАнотація:
Thesis (MScEng)-- Stellenbosch University, 2013.ENGLISH ABSTRACT: Speed-flow-density relationships are the most useful tools in the highway design and planning process. They are useful in predicting the roadway capacity, in determining the adequate level-of-service of traffic flow and in determining travel time for a given roadway. Two-lane two-way rural highways constitute the vast majority of the rural road network in South Africa. Nowadays in the Western Cape and other provinces of South Africa, the speed-flow-density relationships normally used for rural transportation studies are derived from the Highway Capacity Manual, which reflects the traffic conditions in the North American situation. Since the North American traffic conditions may be different from the South African conditions, a need to investigate speed-flow-density relationships on these highways in South Africa arises in order to justify any investment made on these roads. In this context, a video technique was used to collect traffic flow data during morning peak hours on two rural two-lane two-way highways in the Western Cape Province in order to investigate these relationships. Through the use of Adobe premiere C.S 6 software, travel time of individual vehicles and distance headways were measured and used in computation of average speed and average density. Several researchers have developed models to describe the relationships between traffic characteristics on uninterrupted flow facilities. In this study, some of these models were tested using collected data in order to investigate which model fits the data satisfactorily. Statistical methods were used to evaluate the ability of each model to predict the flow characteristics over the whole range of data. Average speed and density data were used through regression analysis to perform curve fitting and testing of these developed models. In the next stage, the model which provided a best representation of the data on each section was selected and through the application of the steady-state equation (2.1), flow-density and speed-flow relationships were established on these sections. The available data were also used to investigate the impact the observation time has on the speed-flow curve and the resulting capacity value. Finally, the developed speed-flow curves were used to determine the capacities of the study sections. These capacity values were used to determine if the shoulder usage contributes in increasing the capacity of two-lane two-way highways by comparing them to the capacity provided by HCM.
AFRIKAANSE OPSOMMING: Spoed-vloei-digtheid verhoudings is baie handig in die beplanning en ontwerp van paaie. Dit kan ook gebruik word in die voorspelling van kapasiteit, diensvlak en reistyd. Twee-laan twee-rigting paaie maak die grootste deel van die Suid-Afrikaanse padnetwerk uit en vir die beplanning daarvan word van Amerikaanse spoed-vloei-digtheid verhoudings gebruik gemaak aangesien daar nog nie voorheen ‘n studie hiervan in SA gemaak is nie. Video-opnames is gebruik om verkeersvloeidata op twee paaie in die omgewing van Stellenbosch te versamel. Die reistyd en digtheid van individuele voertuie is tydens spitstye waargeneem. Die data is gebruik om te bepaal watter modelle die beste is om die spoed-vloei-digtheid verhoudings vir hierdie paaie te modelleer. Die beste modelle is dan gebruik om die kapasiteit van die paaie te bepaal en dit te vergelyk met die Amerikaanse waardes.
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Anany, Hossam. "Effectiveness of a Speed Advisory Traffic Signal System for Conventional and Automated vehicles in a Smart City." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-156650.
Повний текст джерелаАнотація:
This thesis project investigates the state-of-the-art in traffic management "Green Light Optimal Speed Advisory (GLOSA)" for vehicles in a smart city. GLOSA utilizes infrastructure and vehicles communication through using current signal plan settings and updated vehicular information in order to influence the intersection approach speeds. The project involves traffic microscopic simulations for a mixed traffic environment of conventional and automated vehicles (AVs) both connected to the intersection control and guided by a speed advisory traffic management system. Among the project goals is to assess the effects on traffic performance when human drivers comply to the speed advice. The GLOSA management approach is accessed for its potential to improve traffic efficiency in a full market penetration of connected AVs with absolute compliance. The project also aims to determine the possible outcome resulting from enhancing the AVs capabilities such as implementing short time headways between vehicles in the future. The best traffic performance results achieved by operating GLOSA goes for connected AVs with the lowest simulated time headway (0.3 sec). The waiting time reduction reaches 95% and trip delay lessens to 88 %.
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Bennett, Logan Stewart. "Analysis of Benefits of an Expansion to UDOT's Incident Management Program." BYU ScholarsArchive, 2021. https://scholarsarchive.byu.edu/etd/9250.
Повний текст джерелаАнотація:
In 2018 the Utah Department of Transportation (UDOT) funded a study in which data were collected to evaluate performance measures for UDOT's Incident Management Team (IMT) program. After that study was completed, UDOT received funding to expand the size of its IMT program. Additionally, TransSuite, a data source used by the UDOT Traffic Operations Center to log incident-related data, was reconfigured to provide a higher quantity of performance measure data. This study made use of the new data source, in addition to Computer Aided Dispatch logs provided by the Utah Highway Patrol that were used in the first study, to collect performance measure data of the expanded program and measure the impacts of the IMT program expansion. Using these two datasets, a reanalyzed 2018 dataset and a new 2020 dataset, a comparison of performance measures was made. Performance measures studied included those defined as important by the Federal Highway Administration's Focus States Initiative in 2009, namely Roadway Clearance Time, Incident Clearance Time, and Response Time. These performance measures were calculated for IMT responders at 320 incidents in 2018 and 289 incidents in 2020. In addition, data regarding the affected volume associated with incidents, the excess travel time accumulated due to incidents, and the excess user cost associated with incident congestion were gathered. In 2018, 188 incidents were analyzed for these user impacts, and in 2020 144 incidents were analyzed. Statistical analyses were conducted to compare IMT performance between the two years and to determine relationships between performance measures and user impacts. The effects of the COVID-19 pandemic affected traffic volumes during this study, and statistical analyses were adjusted to account for volume differences between the two years. Results indicated that the expansion of the IMT program has allowed UDOT to respond faster to incidents, and respond to a larger quantity of incidents over a larger coverage area and in extended operating hours. Performance of the expanded IMT program has had significant effects in reducing incident-related congestion and its costs.
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Wood, Nicholas Stephen. "Assessing the marginal cost of freeway congestion for vehicle fleets using passive GPS speed data." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34798.
Повний текст джерелаАнотація:
This thesis examines the marginal cost of congested travel to a variety of businesses by observing time spent in congestion and estimating excess labor costs based upon the relevant value of time. The fleets in the scoping study represented commercial deliveries of goods and services, government agencies, and transit systems. Observations on limited-access expressways within the 13-county Atlanta metropolitan region were used in the analysis. Vehicles were monitored by using a passive GPS assembly that transmitted speed and location data in real-time to an off-site location. Installation and operation during the observation period required no interaction from the driver. Over 217 hours of good freeway movement during 354 vehicle-days was recorded. Rates of delay, expressed as a unit of lost minutes per mile traveled, were calculated by taking the difference in speeds observed during congestion from an optimal free-flow speed of 45 mph and dividing that by the distance traveled per segment. The difference between the 50th and 95th percentile delay rates was used as the measure for travel unreliability. Daily average values of extra time needed per fleet vehicle to ensure on-time arrivals were derived, and the median buffer across all fleets was 1.65 hours of added time per vehicle. Weekly marginal costs per fleet vehicle were estimated by factoring in the corresponding driver wages or hourly operation costs (for transit fleets). Equivalent toll rates were calculated by multiplying the 95th percentile delay rate by the hourly costs. The equivalent toll per mile traveled was representative of an equal relationship between the marginal costs of congestion experienced and a hypothetical state of free-flow travel (under first-best rules of marginal cost pricing). The median equivalent toll rates across all fleets was $0.43 per mile for weekday mornings, $0.13 per mile for midday weekdays, $0.53 per mile for afternoon weekdays and $0.01 per mile for weekday nights and weekends.
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Downey, Matthew Blake. "Evaluating the Effects of a Congestion and Weather Responsive Advisory Variable Speed Limit System in Portland, Oregon." PDXScholar, 2015. https://pdxscholar.library.pdx.edu/open_access_etds/2397.
Повний текст джерелаАнотація:
Safety and congestion are ever present and increasingly severe transportation problems in urban areas throughout the nation and world. These phenomena can have wide-ranging consequences relating to safety, the economy, and the environment. Adverse weather conditions represent another significant challenge to safety and mobility on highways. Oregon is not immune from either of these global issues. Oregon Route (OR) 217, to the southwest of the downtown Portland, is one of the worst freeways for congestion in the state and is also subject to the Pacific Northwest's frequently inclement and unpredictable climate. High crash rates, severe recurrent bottlenecks and highly unreliable travel times continuously plague the corridor, making it a major headache for the thousands of commuters using it every day.
In an effort to more effectively combat both congestion and adverse weather, transportation officials all over the world have been turning to increasingly technological strategies like Active Traffic Management (ATM). This can come in many forms, but among the most common are variable speed limit (VSL) systems which use real-time data to compute and display appropriate reduced speeds during congestion and/or adverse weather. After numerous studies and deliberations, Oregon Department of Transportation (ODOT) selected Oregon Route (OR) 217 as one of the first locations in the state to be implemented with an advisory VSL system, and that system began operation in the summer of 2014. This thesis seeks to evaluate the effectiveness of this VSL system through the first eight months of its operation through an in-depth and wide-ranging "before and after" analysis.
Analysis of traffic flow and safety data for OR 217 from before the VSL system was implemented made clear some of the most prevalent issues which convinced ODOT to pursue VSL. Using those issues as a basis, a framework of seven specific evaluation questions relating to both performance and safety, as well as both congestion and adverse weather, was established to guide the "before and after" comparisons. Hypotheses, and measures of effectiveness for each question were developed, and data were obtained from a diverse array of sources including freeway detectors, ODOT's incident database, and the National Oceanic and Atmospheric Administration (NOAA).
The results of the various "before and after" comparisons performed as a part of this thesis indicate that conditions have changed on OR 217 in a number of ways since the VSL system was activated. Many, but not all, of the findings were consistent with the initial hypotheses and with the findings from other VSL studies in the literature. Certain locations along the corridor have seen significant declines in speed variability, supporting the common notion that VSL systems have a harmonizing effect on traffic flow. Crash rates have not decreased, but crashes have become less frequent in the immediate vicinity of VSL signs. Flow distribution between adjacent lanes has been more even since VSL implementation during midday hours and the evening peak, and travel time reliability has seen widespread improvement in three of the corridor's four primary travel lanes during those same times. The drops in flow that generally occur upstream of bottlenecks once they form have had diminished magnitudes, while the drops in flow downstream of the same bottlenecks have grown. Finally, the increase in travel times that is usually brought about by adverse weather has been smaller since VSL implementation, while the decline in travel time reliability has largely disappeared.
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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.
Повний текст джерелаАнотація:
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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Morozova, Nadezhda S. "Utilizing High Resolution Data to Identify Minimum Vehicle Emissions Cases Considering Platoons and EVP." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/78885.
Повний текст джерелаАнотація:
This paper describes efforts to optimize the parameters for a platoon identification and accommodation algorithm that minimizes vehicle emissions. The algorithm was developed and implemented in the AnyLogic framework, and was validated by comparing it to the results of prior research. A four-module flowchart was developed to analyze the traffic data and to identify platoons. The platoon end time was obtained from the simulation and used to calculate the offset of the downstream intersection. The simulation calculates vehicle emissions with the aid of the VT-Micro microscopic emission model. Optimization experiments were run to determine the relationship between platoon parameters and minimum- and maximum-emission scenarios. Optimal platoon identification parameters were found from these experiments, and the simulation was run with these parameters. The total time of all vehicles in the simulation was also found for minimum and maximum emissions scenarios. Time-space diagrams obtained from the simulations demonstrate that optimized parameters allow all cars to travel through the downstream intersection without waiting, and therefore cause a decrease in emissions by as much as 15.5%.
This paper also discusses the outcome of efforts to leverage high resolution data obtained from WV-705 corridor in Morgantown, WV. The proposed model was developed for that purpose and implemented in the AnyLogic framework to simulate this particular road network with four coordinated signal-controlled intersections. The simulation was also used to calculate vehicle CO, HC, NOx emissions with the aid of the VT-Micro microscopic emission model. Offset variation was run to determine the optimal offsets for this particular road network with traffic volume, signal phase diagram and vehicle characteristics. A classifier was developed by discriminant analysis based on significant attributes of HRD. Equation of this classifier was developed to distinguish between set of timing plans that produce maximum emission from set of timing plans that produce maximum emission. Also, current work investigates the potential use of the GPS-based and similar priority systems by giving preemption through signalized intersections. Two flowcharts are developed to consider presence of emergency vehicle (EV) in the system so called EV life cycle and EV preemption (EVP). Three scenarios are implemented, namely base case scenario when no EV is involved, EV scenario when EV gets EVP only, and EV scenario when EV gets preemption by signals and right-of-way by other vehicles. Research makes an attempt to compare emission results of these scenarios to find out whether EV effects vehicle emission in the road network and what is the level of this influence if any.Master of Science
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黃依凡 and Yee-fang Eva Wong. "A study of the transport needs of patients for medical services, with special emphasis on cost minimization." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B42576313.
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Zhang, Li, and Xi Ren. "A two-factor evaluation of bus delays based on GIS-T database and simulation." Thesis, Högskolan i Gävle, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-7985.
Повний текст джерелаАнотація:
During the urbanization process, vehicles quantity increase with expansion in population. Under this situation, bus transportation system also suffers from bus delay. Bus delay could be caused by a series of factors, for instance, overload passengers, traffic jam, traffic accident and other unpredictable situations. Therefore, choosing crucial elements to efficiently evaluate bus delay is a complex problem in bus delay researches and operation management. The thesis propose an approach to evaluate and explain bus delay by two elements: traffic congestion and passengers’ waiting time. Those two elements would represent the action of external and internal factors on bus operation. This approach could be adaptive to explain the reasons for bus delays, thus to help the optimization of bus lines and give useful information for decision making of transportation company. To achieve the research aim, a GIS-T database was created by combining the GIS database and TIS database. Spatial data as well as attribute data are combined in the database to represent the crucial information for bus delay. Based on GIS-T the database, the impact of traffic congestion and passengers’ waiting time was calculated using the bus line simulation. By implementing the above steps, the main cause of bus delay was studied. A case study application of this method is narrated; focusing on optimize the bus system of Guiyang city, South China. Different methods are used to find out the problem of system and the reason for delay. Moreover, optimization suggestion is proposed according to result. Compared with other methods, the two-factor method has the advantage of locating the reason of delay for each station. The time performance is not superior to other methods. By comparing the situation of adjacent station, the proportion of traffic congestion and overload passenger in bus delay was determined. The two-factor method is applicable for other transit system in different cities which has similar structure as Guiyang. However, for cities with other structure, a feasibility should be made to select an appropriate model.
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Cheng, Hua. "Hydrodynamic control of retention in heterogeneous aquifers and fractured rock." Doctoral thesis, Stockholm : KTH Architecture and the Built Environment, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-496.
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Jepson, Dale. "Enhancing public transport operations on arterial roads." Thesis, Queensland University of Technology, 1998. https://eprints.qut.edu.au/36092/1/36092_Jepson_1998.pdf.
Повний текст джерелаАнотація:
Bus priority treatments such as busways, bus lanes and bus priority at traffic signals are all utilised in Australian metropolitan areas. These treatments are designed to reduce the travel time for buses and make this transportation mode more efficient and attractive. The common applications of such treatments for Australian
conditions are assessed in this research to identify the travel time impacts of introducing bus priority. This will assist in the selection of bus priority measures on
arterial roads for Australian conditions. The methodology applied here entails the identification of optimum conditions for using typical bus priority treatments.
This research identifies the number of bus passengers necessary to justify various forms of bus priority treatments with varying traffic conditions. The traffic
conditions modelled varied from low through to high degree of saturation for general purpose traffic on the road network. The resultant analyses demonstrated that as the degree of saturation increases, higher numbers of bus passengers are necessary to justify reducing the capacity by introducing bus priority. It is concluded however that
an economic analysis using travel time costs should not be the only criteria used to identify the appropriate bus priority treatment. It is suggested that bus priority should be part of an overall traffic management approach in conjunction with cost disincentives to cars and appropriate marketing for public transport. The current trends in bus priority treatments are addressed by considering a case study for the Gold Coast Highway located on Queensland's Gold Coast. This work
provides an evaluation of bus priority treatments and conditions for justification for such measures. The research summarises the impact of introducing bus lanes, transit lanes, bus priority at traffic signals and improved passenger information and ticketing systems for the Gold Coast Highway. The analysis indicates that journey time saving for buses of up to 20 percent may be achieved with these bus priority treatments.
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Wang, Liang. "Design, Data Collection, and Driver Behavior Simulation for the Open- Mode Integrated Transportation System (OMITS)." Thesis, 2016. https://doi.org/10.7916/D82F7N7S.
Повний текст джерелаАнотація:
With the remarkable increase in the population and number of vehicles, traffic has become a severe problem in most metropolitan areas. Traffic congestion has imposed tight constraints on economic growth, national security, and mobility of riders and goods. The open-mode integrated transportation system (OMITS) has been designed to improve the traffic condition of roadways by increasing the ridership of vehicles and optimizing transportation modes through smart services integrating emerging information communication technologies, big data management, social networking, and transportation management. Even a modest reduction in the number of vehicles on roadways will lead to a considerable cost savings in terms of time and money. Additionally the reduction in traffic jams will lead to a significant decrease in both gasoline consumption and greenhouse gas emissions.
As a result, novel transportation management is critical to reduce vehicle mileage in the peak time of the road network. The OMITS was proposed to enhance transportation services in respect to the following three aspects: optimization of the transportation modes by multimodal traveling assignment, dynamic routing and ridesharing service with advanced traveler information systems, and interactive user interface for social networking and traveling information. Therefore, the OMITS encompasses a broad range of advanced transportation research topics, say dynamic trip- match, transportation-mode optimization, traffic prediction, dynamic routing, and social network- based carpooling.
This dissertation will focus on a kernel part of the OMITS, namely traffic simulation and prediction based on data containing the distribution of vehicles and the road network configuration. A microscopic traffic simulation framework has been developed to take into account various traffic phenomena, such as traffic jams resulting from bottlenecking, incidents, and traffic flow shock waves. Four fundamental contributions of the present study are summarized as follows:
Firstly, an accurate and robust vehicle trajectory data collection method based on image data of unmanned aerial vehicle (UAV) has been presented, which can be used to rapidly and accurately acquire the real-time traffic conditions of the region of interest. Historically, a lack in the availability of trajectory data has posed a significant obstacle to the enhancement of microscopic simulation models. To overcome this obstacle, a UAV based vehicle trajectory data collection algorithm has been developed. This method extracts vehicle trajectory data from the UAV’s video at different altitudes with different view scopes. Compared with traditional methods, the present data collection algorithm incorporates many unique features to customize the vehicle and traffic flow, through which vehicle detection and tracking system accuracy can be considerably increased.
Secondly, an open mechanics-based acceleration model has been presented to simulate the longitudinal motion of vehicles, in which five general factors—namely the subject vehicle’s speed and acceleration sensitivity, safety consideration, relative speed sensitivity and gap reducing desire—have been identified to describe drivers’ preferences and the interactions between vehicles. Inspired by the similarity between vehicle interactions and particle interactions, a mechanical system with force elements has been introduced to quantify the vehicle’s acceleration. Accordingly, each of the aforementioned five factors are assumed to function as an individual trigger to alter each vehicle’s speed. Based on Newton’s second law of motion, the subject vehicle’s longitudinal behavior can be simulated by the present open mechanics-based acceleration model. By introducing feeling gap, multilane acceleration behavior is included in the presented model. The simulation results fit realistic conditions for the traffic flow and the road capacity very well, where traffic shockwaves can be observed for a certain range of the traffic density. This model can be extended to more general scenarios if other factors can be recognized and introduced into the modeling framework.
Thirdly, a driver decision-based lane change execution model has been developed to describe a vehicle’s lane change execution process, which includes two steps, i.e. driver’s lane selection and lane change execution. Currently, most lane change models focus on the driver’s lane selection, and overlook the driver’s behavior during a process of lane change execution which plays a significant role in the simulation of traffic flow characteristics. In this model, a lane change execution is analyzed as a driver’s decision-making process, which consists of desire point setting, priority decision-making, corresponding actions and achievement of consensus analysis.
Compared with the traditional lane change execution models, the present model describes a realistic lane change process, and it provides more accurate and detailed simulation results in the microscopic traffic simulation.
Based on the presented open mechanics-based acceleration model and the driver decision- based lane change execution model, a reverse lane change model has further been developed to simulate some complex traffic situations such as reverse lane change process at a two-way-two- lane road section where one lane is blocked by a traffic incident. Based on this reverse lane change model, information on the average waiting time and road capability can be obtained. The simulation results show that the present model is able to reflect real driver behavior and the corresponding traffic phenomenon during a reverse lane change process
Through a homogenization process of the microscopic vehicle motion, we can obtain the macroscopic traffic flow of the roadway network within certain time and spatial ranges, which will be integrated into the OMITS system for traffic prediction. The validation of the models through future OMITS operations will also enable them to be high fidelity models in future driverless technologies and autonomous vehicles.
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"Integrated Model of the Urban Continuum with Dynamic Time-dependent Activity-Travel Microsimulation: Framework, Prototype, and Implementation." Doctoral diss., 2012. http://hdl.handle.net/2286/R.I.14529.
Повний текст джерелаАнотація:
abstract: The development of microsimulation approaches to urban systems modeling has occurred largely in three parallel streams of research, namely, land use, travel demand and traffic assignment. However, there are important dependencies and inter-relationships between the model systems which need to be accounted to accurately and comprehensively model the urban system. Location choices affect household activity-travel behavior, household activity-travel behavior affects network level of service (performance), and network level of service, in turn, affects land use and activity-travel behavior. The development of conceptual designs and operational frameworks that represent such complex inter-relationships in a consistent fashion across behavioral units, geographical entities, and temporal scales has proven to be a formidable challenge. In this research, an integrated microsimulation modeling framework called SimTRAVEL (Simulator of Transport, Routes, Activities, Vehicles, Emissions, and Land) that integrates the component model systems in a behaviorally consistent fashion, is presented. The model system is designed such that the activity-travel behavior model and the dynamic traffic assignment model are able to communicate with one another along continuous time with a view to simulate emergent activity-travel patterns in response to dynamically changing network conditions. The dissertation describes the operational framework, presents the modeling methodologies, and offers an extensive discussion on the advantages that such a framework may provide for analyzing the impacts of severe network disruptions on activity-travel choices. A prototype of the model system is developed and implemented for a portion of the Greater Phoenix metropolitan area in Arizona to demonstrate the capabilities of the model system.Dissertation/Thesis
Ph.D. Civil and Environmental Engineering 2012