Dissertations / Theses on the topic 'Traffic flow Research Australia'

Interstate highways are one of the most important components of the transportation infrastructure in America. Freeway ramps play an important role in the whole interstate transportation system. This paper researches the traffic flow characteristics of four typical exit ramps in USA, which are tapered one-lane exit, tapered two-lane exit, parallel one-lane exit and parallel two-lane exit. Computer simulation software, such as CORSIM and HCS are applied as the main tools in this research. ANOVA and Tukey are used for statistical purpose. It compares the maximum capacity, average running speed and the total lane change number of those four exit ramps. It is found that no matter in terms of traffic discharging rate or total lane charging number; the tapered two-lane exit has the best operational performance. Tapered one-lane exit ramp has the least capacity. Parallel one-lane exit and parallel two-lane exit have very limited traffic operational difference in terms of capacity and running speed. It is recommended that parallel two-lane exit ramp should not be designed along the freeway if the right of way along arterial road is enough. It is observed from the simulation data that the grade of freeway, truck percentage, restricted to the truck use of certain lane(s) and the location of exit sign have significant impact on the running speed and total lane change number. An uphill can decrease the running speed dramatically while more truck brings more lane change, causing safety concerns. It is found that when trucks are restricted to the right two most lane, there will be less lane change number comparing with trucks are not restricted. Location of exit sign operates well at the distance between 4000 ft to 5000 ft. does have a significant impact on the operational speed and total lane change number before, within or after functional area of an exit, based on the data analysis of simulation runs.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 137-140).
The cost of air traffic delays is well documented, and furthermore, it is known that the significant proportion of delays is incurred at airports. Much of the air traffic flow management literature focuses on traffic flows between airports in a network, and when studies have focused on optimizing airport operations, they have focused largely on a single aspect at a time. In this thesis, we fill an important gap in the literature by proposing unified approaches, on both strategic and tactical levels, to optimizing the traffic flowing through an airport. In particular, we consider the entirety of key problems faced at an airport: a) selecting a runway configuration sequence; b) determining the balance of arrivals and departures to be served; c) assigning flights to runways and determining their sequence; d) determining the gate-holding duration of departures and speedcontrol of arrivals; and e) routing flights to their assigned runway and onwards within the terminal area. In the first part, we propose an optimization approach to solve in a unified manner the strategic problems (a) and (b) above, which are addressed manually today, despite their importance. We extend the model to consider a group of neighboring airports where operations at different airports impact each other due to shared airspace. We then consider a more tactical, flight-by-flight, level of optimization, and present a novel approach to optimizing the entire Airport Operations Optimization Problem, made up of subproblems (a) - (e) above. Until present, these have been studied mainly in isolation, but we present a framework which is both unified and tractable, allowing the possibility of system-optimal solutions in a practical amount of time. Finally, we extend the models to consider the key uncertainties in a practical implementation of our methodologies, using robust and stochastic optimization. Notable uncertainties are the availability of runways for use, and flights' earliest possible touchdown/takeoff times. We then analyze the inherent trade-off between robustness and optimality. Computational experience using historic and manufactured datasets demonstrates that our approaches are computationally tractable in a practical sense, and could result in cost benefits of at least 10% over current practice.
by Michael Joseph Frankovich.
Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2012.
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 (p. 151-154).
We propose a tractable optimization framework for network Air Traffic Flow Management (ATFM) with an eye towards the future. The thesis addresses two issues in ATFM research: a) fairness and collaboration amongst airlines; and b) uncertainty inherent in capacity forecasts. A unifying attraction of the overall dissertation is that the Collaborative Decision-Making (CDM) paradigm, which is the current philosophy governing the design of new ATFM initiatives, is treated as the starting point in the research agenda. In the first part of the thesis, we develop an optimization framework to extend the CDM paradigm from a single-airport to a network setting by incorporating both fairness and airline collaboration. We introduce different notions of fairness emanating from a) First-Scheduled First-Served (FSFS) fairness; and b) Proportional fairness. We propose exact discrete optimization models to incorporate them. The first fairness paradigm which entails controlling number of reversals and total amount of overtaking is especially appealing in the ATFM context as it is a natural extension of Ration-By-Schedule (RBS). We allow for further airline collaboration by proposing discrete optimization models for slot reallocation. We provide empirical results of the proposed optimization models on national-scale, real world datasets that show interesting tradeoffs between fairness and efficiency. In particular, schedules close to the RBS policy (with single digit reversals) are possible for a less than 10% increase in delay costs. We utilize case studies to highlight the considerable improvements in the internal objective functions of the airlines as a result of slot exchanges. Finally, the proposed models are computationally tractable (running times of less than 30 minutes). In the second part, we address the important issue of capacity uncertainty by presenting the first application of robust and adaptive optimization in the ATFM problem. We introduce a weather-front based approach to model the uncertainty inherent in airspace capacity estimates resulting from the impact of a small number of weather fronts. We prove the equivalence of the robust problem to a modified instance of the deterministic problem; solve the LP relaxation of the adaptive problem using affine policies; and report extensive empirical results to study the inherent tradeoffs.
by Shubham Gupta.
Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2010.
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 (p. 121-123).
In this thesis, we develop multi-resource integer optimization formulations for coordinating Traffic Flow Management (TFM) programs with equity considerations. Our multi-resource approaches ignore aircraft connectivity between flights, but allow a single flight to utilize multiple capacity-controlled resources. For example, when both Ground Delay Programs (GDPs) and Airspace Flow Programs (AFPs) are simultaneously in effect, a single flight may be impacted by a GDP and one or more AFPs. We show that due to the similarity with current practice, our models can be applied directly in the current Collaborative Decision-Making (CDM) environment. In the first part of the thesis, we develop these formulations as extensions of a well-studied, existing nationwide TFM formulation and compare them to approaches utilized in practice. In order to make these comparisons, we first develop a metric, Time-Order Deviation, for evaluating schedule fairness in the multi-resource setting. We use this metric to compare approaches in terms of both schedule fairness and allocated flight delays. Using historical scenarios derived from 2007 data, we show that, even with limited interaction between TFM programs, our Ration-by-Schedule Exponential Penalty model can improve the utilization of air transportation system resources. Skipping ahead, in the last part of the thesis, we develop a three-stage sequential evaluation procedure in order to analyze the TFM allocation process in the context of a dynamic CDM environment. To perform this evaluation we develop an optimization-based airline disruption response model, which utilizes passenger itinerary data to approximate the underlying airline objective, resulting in estimated flight cancellations and aircraft swaps between flight legs. Using this three-stage sequential evaluation procedure, we show that the benefits of an optimization-based allocation are likely overstated based on a simple flight-level analysis. The difference between these results and those in the first part of the thesis suggests the importance of the multi-stage evaluation procedure. Our results also suggest that there may be significant benefits to incorporating aircraft flow balance considerations into the Federal Aviation Administration's (FAA's) TFM allocation procedures. The passenger itinerary data required for the airline disruption response model in the last part of the thesis are not publicly available, thus in the second part of the thesis, we develop a method for modeling passenger travel and delays. In our approach for estimating historical passenger travel, we develop a discrete choice model trained on one quarter of proprietary booking data to disaggregate publicly available passenger demand. Additionally, we extend a network-based heuristic for calculating passenger delays to estimate historical passenger delays for 2007. To demonstrate the value in this approach, we investigate how passenger delays are affected by various features of the itinerary, such as carrier and time of travel. Beyond its applications in this thesis, we believe the estimated passenger itinerary data will have broad applicability, allowing a passenger-centric focus to be incorporated in many facets of air transportation research. To facilitate these endeavors, we have publicly shared our estimated passenger itinerary data for 2007.
by Douglas Fearing.
Ph.D.

The Australian road freight industry is moving towards improved efficiency and competitiveness through the use of larger and more innovative multi-combination vehicles (MCVs). However, this move has brought about concern over the interaction of these new vehicles with the environment, existing infrastructure and other road users. The aim of this research project was to assess the impacts of MCVs on traffic operation and safety. This was undertaken by initially reviewing cunent literature on MCVs. It was recognised that the Australian heavy vehicle fleet had modernised since a number of performance levels were established and the review highlighted the need for greater research to obtain current data and either develop new performance levels or validate previous research. This study selected four characteristics for analysis: passenger car equivalence (PCE), clearance time, acceleration, and tracking ability on a straight path. These characteristics were considered to be the most influential on the interaction between MCVs and other road users. Vehicle operational data was collected between April and August 2001, for each characteristic, via a series of three in-field test programs located on controlled road sections in Queensland: south of Charters Towers; west of Toowoomba; and at the Mount Cotton Training Centre, south-east of Brisbane. All tested MCVs recorded a PCE greater than 2 for a through-movement on a flat grade with no adjacent traffic lanes. It was determined that assuming a constant PCE does not account for the variation in values attained for different MCV types. Under circumstances where MCV volumes are significant, it would be more accurate to establish the average PCE value of each relevant movement at the intersection based on PCEs across the traffic spectrum and using the values provided in Table 5.4. Further testing is needed to establish PCE values on grades, turning movements, non-standard lane widths, and for vehicles such as Double Road Trains, AB-Triples and AAB-Quads. The intersection clearance time characteristics proposed by NRTC (2001) were found to be conservative for the MCV s tested. To cover a greater range of operating conditions, clearance time requirements for a MCV on a particular grade may be derived from the trajectory curves provided in Figures 6.3 to 6.6. Further in-field testing should be undertaken to obtain additional trajectory curves for MCVs with lower powered engines. Speed curves were developed (Figures 6.9 to 6.12) which may be used with the above trajectory curves to derive vehicle speeds at specific distances, on particular grades. This would enable assessors to determine the minimum entry lane length required to allow a MCV to attain adequate speed to merge into moving traffic, and also indicate whether an overtaking lane is required on a steep ascending grade. Further testing should be undertaken to establish speed curves over a higher speed and distance range . . Queensland Department of Main Roads (1998b) recommended an average acceleration rate for use in sight distance calculations. This was found from testing to be generally conservative for a B-Double, although too high for all the other MCVs tested. The trajectory curves provided in Figures 6.15 to 6.18 were developed to examine the variation in acceleration as test vehicles depart from rest. These may be used to determine average acceleration rates, over specific distances and on particular grades. Alternatively, sight distance requirements may be determined from equation (6.9), using clearance times established from equation (6.5) or Figures 6.3 to 6.6. Data on tracking ability of MCVs on a straight path was collected. It is recommended that further work be conducted to analyse the data, determine lane width requirements, and variations in tracking ability between separate trailers. The findings should be compared with Prem et al. (2000) and NRTC (2001) values. Further work is also required to identify which factors most influence lateral displacement of the rear trailer. It is expected that the research findings will be used to inform development of Queensland Department of Main Roads' Route Assessment Guidelines and potentially those of other authorities.

The role of walking in the development of healthy, livable communities is being increasingly recognized. In urban areas, intersections represent locations where different modes converge, and are often viewed as deterrents to walking. This is due to the unwarranted and often unnecessary delays imposed by signal timing policies for pedestrians and increased potential for conflicts. Traditional signal timing design prioritizes vehicles over pedestrians leading to undesirable consequences such as large delays and risky pedestrian behaviors. Pedestrians are accommodated in a manner that is designed to cause least interruption to the flow of motor vehicles. This lack of pedestrian accommodation at signalized intersections is the focus of this dissertation. Understanding pedestrian attitudes and perceptions is important because it offers insights into actual crossing behavior at signalized intersections. An intercept survey of 367 crossing pedestrians was undertaken at four signalized intersections in Portland, Oregon, and binary logistic regression models were constructed to quantify the impacts of demographics, trip characteristics and type of infrastructure on pedestrian perceptions and attitudes regarding delay, crossing time and motivators for crossing decisions. Safety was found to have a larger effect than compliance on the decision to cross the street. Pedestrians at recall intersections expressed higher satisfaction with delay than at actuated intersections. Novel methods to measure pedestrian delay using 2070 signal controllers and Voyage software were developed. These methods have been adopted by the City of Portland to record actuation trends and delays at various intersections. In the absence of demand data, pedestrian push button actuations can be considered as a proxy for crossing demand. The micro-simulation software VISSIM was used to analyze delays resulting from varying pedestrian and vehicle volumes on a network of three intersections in Portland, Oregon. From a pedestrian perspective, free operation was found to be always beneficial due to lower pedestrian delays. However, from a system wide perspective, free operation was found to be beneficial only under low-medium traffic conditions from an overall delay reduction viewpoint, while coordinated operation showed benefits under heavy traffic conditions, irrespective of the volume of pedestrians. Control strategies were developed to identify the best mode of signal controller operation that produced the lowest overall average delay per user. A procedure to identify the optimal control strategy based on user inputs (major street volume to capacity ratios and rate of pedestrian phase serviced for the minor street) was developed. The procedure was applied to a network of three intersections in east Portland, OR and the findings were verified. This research offers significant contributions in the field of pedestrian research. The findings related to attitudes and perceptions of crossing pedestrians offer greater insights into pedestrian crossing behavior and add to the body of existing literature. The methods developed to obtain pedestrian actuations and delay data from signal controllers represent an easy and cost-effective way to characterize pedestrian service at intersections. The results pertaining to signal timing strategies represent an important step towards incorporating pedestrian needs at intersections and demonstrate how control strategies employed to benefit pedestrians could benefit the entire system.

Air traffic flow management is a critical component of air transport operations because at some point in time, often very frequently, one of more of the critical resources in the air transportation network has significantly reduced capacity, resulting in congestion and delay for airlines and other entities and individuals who use the network. Typically, these “bottlenecks” are noticed at a given airport or terminal area, but they also occur in en route airspace. The two-stage combinatorial optimization framework for air traffic flow management under constrained capacity that is presented in this thesis, represents a important step towards the full consideration of the combinatorial nature of air traffic flow management decision that is often ignored or dealt with via priority-based schemes. It also illustrates the similarities between two traffic flow management problems that heretofore were considered to be quite distinct. The runway systems at major airports are highly constrained resources. From the perspective of arrivals, unnecessary delays and emissions may occur during peak periods when one or more runways at an airport are in great demand while other runways at the same airport are operating under their capacity. The primary cause of this imbalance in runway utilization is that the traffic flow into and out of the terminal areas is asymmetric (as a result of airline scheduling practices), and arrivals are typically assigned to the runway nearest the fix through which they enter the terminal areas. From the perspective of departures, delays and emissions occur because arrivals take precedence over departures with regard to the utilization of runways (despite the absence of binding safety constraints), and because arrival trajectories often include level segments that ensure “procedural separation” from arriving traffic while planes are not allowed to climb unrestricted along the most direct path to their destination. Similar to the runway systems, the terminal radar approach control facilities (TRACON) boundary fixes are also constrained resources of the terminal airspace. Because some arrival traffic from different airports merges at an arrival fix, a queue for the terminal areas generally starts to form at the arrival fix, which are caused by delays due to heavy arriving traffic streams. The arrivals must then absorb these delays by path stretching and adjusting their speed, resulting in unplanned fuel consumption. However, these delays are often not distributed evenly. As a result, some arrival fixes experience severe delays while, similar to the runway systems, the other arrival fixes might experience no delays at all. The goal of this thesis is to develop a combined optimization approach for terminal airspace flow management that assigns a TRACON boundary fix and a runway to each flight while minimizing the required fuel burn and emissions. The approach lessens the severity of terminal capacity shortage caused by and imbalance of traffic demand by shunting flights from current positions to alternate runways. This is done by considering every possible path combination. To attempt to solve the congestion of the terminal airspace at both runways and arrival fixes, this research focuses on two sequential optimizations. The fix assignments are dealt with by considering, simultaneously, the capacity constraints of fixes and runways as well as the fuel consumption and emissions of each flight. The research also develops runway assignments with runway scheduling such that the total emissions produced in the terminal area and on the airport surface are minimized. The two-stage sequential framework is also extended to en route airspace. When en route airspace loses its capacity for any reason, e.g. severe weather condition, air traffic controllers and flight operators plan flight schedules together based on the given capacity limit, thereby maximizing en route throughput and minimizing flight operators' costs. However, the current methods have limitations due to the lacks of consideration of the combinatorial nature of air traffic flow management decision. One of the initial attempts to overcome these limitations is the Collaborative Trajectory Options Program (CTOP), which will be initiated soon by the Federal Aviation Administration (FAA). The developed two-stage combinatorial optimization framework fits this CTOP perfectly from the flight operator's perspective. The first stage is used to find an optimal slot allocation for flights under satisfying the ration by schedule (RBS) algorithm of the FAA. To solve the formulated first stage problem efficiently, two different solution methodologies, a heuristic algorithm and a modified branch and bound algorithm, are presented. Then, flights are assigned to the resulting optimized slots in the second stage so as to minimize the flight operator's costs.

New dynamic signal control methods such as fuzzy logic and artificial intelligence developed recently mainly focused on isolated intersection. In this study, a Fuzzy Logic Control for a Diamond Interchange incorporating with Fuzzy Ramp System (FLDI) has been developed. The signalization of two closely spaced intersections in a diamond interchange is a complicated problem that includes both increasing the diamond interchange capacity and reduce delays at the same time. The model comprises of three main modules. The Fuzzy Phase Timing module controls the current phase green time extension, the Phase Selection module select the next phase based on the pre-defined phase sequence or phase logics and the Fuzzy Ramp module determines the cycle time of the ramp meter bases on current traffic volumes and conditions of the interchanges and the motorways. The developed FLDI model has been compared with the traffic actuated simulation with respects to flow rates and the average delays of the vehicles. The model of an actual diamond interchange is described and simulated by using AIMSUN (Advanced Interactive Microscopic Simulator for Urban and Non-Urban Network) software. Simulation results show the FLDI model outperformed the traffic actuated models with lower system total travel time, average delay and improvements in downstream average speed and average delay.

Ramp metering, one of the most effective solutions for improving motorway traffic flows, is playing increasingly important role in traffic management systems. Because of its capability to handle nonlinear and non-stationary problems, fuzzy logic based ramp metering algorithms have been always considered as an extremely suitable control measures to handle a complex nonlinear traffic system. This thesis proposes a genetic fuzzy approach to design a traffic-responsive ramp control algorithm for an isolated onramp. For a local ramp meter algorithm, the problem could be described as the inflow optimization of on-ramp, based on the evaluation of motorway traffic condition. If the inflow of on-ramp is considered as the decision variable, the ramp control problem could be treated as a nonlinear optimization problem of maximizing the evaluation function. The adaptive genetic fuzzy approach is actually a control approach to maximize the inflow of on-ramp under the restriction of evaluation function. In this thesis, a well-known fuzzy logic based ramp metering algorithms developed by Bogenberger is introduced and implemented with an on-ramp congestion model of Constellation Drive Interchange in a stochastic microscopic traffic simulator, Aimsun. To improve the performance of fuzzy control system, genetic algorithm is applied to tune the parameterized membership function of each fuzzy input to maintain the flow density of motorway blow the estimated congestion density. The performances of the genetic fuzzy logic control ramp metering are compared with FLC (fuzzy logic control) ramp metering by means of the percentage change of TTT (Total Travel Time) based on no control condition in Aimsun. The simulation results show the genetic fuzzy ramp metering has a more significant improvement on TTT and more strong stability to maintain system flow density than FLC ramp metering.

Thesis (PhD)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The design of railway station environments in South Africa and to a certain extent internationally, is based on rules of thumb. These rules, using general macroscopic principles for determining peak passenger loads are inadequate and misleading for detailed design purposes. The principles advocated in local design guideline documents are erroneous and ignore the highly variable flow nature or “micro-peaking” effects that typically occur within railway station environments. Furthermore, there are no procedures proposed in these guideline documents, which leads to ambiguous assessment techniques used by practitioners in the determination of pedestrian spatial areas. It is evident that the knowledge in the area of pedestrian movement contained within the design guidance is far from comprehensive. Without a reliable method for estimating pedestrian levels-of-service and capacities, design of new facilities does not follow a uniform process, resulting in high levels of uncertainty in determining if the time, money and resources invested in upgrading facilities will actually cater to the demand. The situation is further exacerbated by current industry thinking towards pedestrian modelling in South Africa, where it is perceived by both clients and practitioners to be more cost effective to use macroscopic techniques and designing infrastructure according to a “one-level-up” level-of-service method. Working with architects confirmed that the area of circulation design was lacking in data and guidance and that associated quantified assessments of pedestrian movement was rarely, if ever, carried out. Towards addressing these issues, the development of a Spatial Parameter (SP)-model spreadsheet application became the main objective of the study. The model contributes towards addressing the needs of individual station users based on the trade-off between level-of-service and infrastructure costs. The output of the model allows the designer to avoid the under-provision (detrimental to operations) and oversizing of railway station infrastructure (with obvious financial implications). The author recognised the lack of pedestrian movement data in South Africa and addressed this by conducting extensive video-based pedestrian observations aimed at exploring the macroscopic fundamental relationships and the ways in which these relationships might be influenced by the various personal, situational and environmental factors that characterise the context in which pedestrians move. The movement trajectories of 24,410 pedestrians were investigated over three infrastructure environments at Maitland and Bonteheuwel stations in Cape Town, carefully selected to incorporate the cultural diversity common in South Africa. Tracking of pedestrians was achieved via the use of an in-house developed “video annotator” software tool. Boarding and alighting rates of 7,426 passengers were also observed at these stations incorporating contributory attributes such as age, gender, body size, encumbrance, group size, time of day, and location. The research makes a number of significant advances in the understanding of pedestrian flow behaviour within railway station environments and provides recommendations to industry of what issues to consider. The empirical study has provided comprehensive pedestrian movement characteristics incorporating the relationships between density, speed and flow including the effect of culture and other context factors unique to the local South African environment. New methods for determining spatial requirements are proposed, together with new and unique empirical data for use by the local industry. A calibrated spreadsheet SP-model for assessing the design of concourse type railway stations is developed and presented in the study. The advance in local pedestrian flow knowledge, together with the SP-model, is shown to be practical through application to two real railway station case study projects. The results of this study constitute an important contribution to local pedestrian flow knowledge and is considered a valuable resource for those developing pedestrian models in practice. It is expected that the results will be useful in the planning and design of pedestrian environments in South African railway stations and can be applied to other African metro railway stations with similar pedestrian characteristics. Overall, this research has succeeded in advancing the approach to railway station design, empirical data, knowledge and methods held within the local engineering industry. However, the contribution of this study and associated conference papers is an early step in changing the perceptions in this country towards ensuring fully informed and appropriate performance-based spatial designs.
AFRIKAANSE OPSOMMING: Die ontwerp van areas binne Suid-Afrikaanse spoorweg stasies en ook tot ‘n sekere mate internasionaal, is gebaseer op historiese ondervindings asook riglyne wat tans in die praktyk gebruik word. Die riglyne gebruik algemene makroskopiese beginsels om die spits passasiersvrag te bepaal vir gedetaileerde ontwerp doeleindes. Hierdie riglyne is egter ongeskik en misleidend aangesien dit nie die hoogs wispelturige natuur van vloei en mikrospits effekte wat binne die stasies plaasvind, in ag nie. Die riglyne ontbreek ook van prosedures wat gevolg moet word vir die bepaling van ruimtelike areas vir voetgangers wat die gevolg het dat dubbelsinnige beramingstegnieke deur praktisyne gebruik word. Die kennis oor voetganger bewegings in die ontwerp riglyne is nie omvattend genoeg nie. Sonder ‘n betroubare beramings metode vir die bepaling van voetganger diensvlak en kapasiteit kan daar nie bepaal word of die tyd, geld en hulpbronne wat in die fasilitieit geinvesteer word, aan die behoeftes gaan voldoen nie. Die situasie word verder vererger deur die huidige persepsie oor voetganger modellering in Suid-Afrika, waar dit deur beide kliënte en praktisyne, as ‘n meer koste effektiewe oplossing gesien word om makroskopiese tegnieke te gebruik en om infrastruktuur te ontwerp volgens ‘n metode waar ‘n hoër diensvlak as die teiken diensvlak gebruik word. In samewerking met argitekte is dit bevestig dat die area van sirkulasie ontwerp ‘n tekort het aan data en riglyne en dat die kwantitatiewe skattings verbonde aan voetganger beweging selde, indien ooit, uitgevoer word. Die ontwikkeling van ‘n Spatial Parameters (SP)-model om die bogenoemde problem te oorkom, is die hoofdoel van hierdie tesis. Die model poog om die behoeftes van individuele stasie gebruikers aan te spreek gebaseer op die wisselwerking tussen diensvlak en infrastruktuur kostes. Die uitsette van die model stel die ontwerper in staat om ondervoorsiening en oorvoorsiening van spoorweg stasie infrastruktuur te voorkom wat nadelige vir die bedryf is en ook ooglopende finansiële implikasies tot gevolg het. Die skrywer het die tekort aan data aangaande voetganger bewegings in Suid-Afrika geidentifiseer en dit aangespreek deur omvattende video gebaseerde voetganger waarnemings te maak met die doel om die basiese makroskopiese verhoudings te ondersoek asook in hoe ‘n mate hierdie verhoudings beinvloed word deur verskeie persoonlike, liggings- en omgewingsfaktore wat die konteks waarin voetgangers beweeg, karakteriseer. Die bewegingsprofiel van 24,410 voetgangers is ondersoek by drie infrastruktuur omgewings by Maitland en Bonteheuwel stasies in Kaapstad. Die stasies is noukeurig uitgesoek om Suid-Afrika se kulturele diversiteit te verteenwoordig. Die voetgangers is nagevolg deur gebruik te maak van ‘n selfontwikkelde video-annoteerder sagteware. Waarneming van die opklim- en afklimspoed van 7,426 passasiers is gemaak by hierdie stasies en faktore soos ouderdom, geslag, liggaamsgrootte, mobiliteit, grootte van groepe, tyd van die dag en ligging was ingesluit by die waarnemings. Hierdie navorsing maak belangrike bydraes tot die begrip van die vloei van voetgangers binne spoorweg stasies en aanbevellings word aan die industrie gemaak oor die faktore wat in ag geneem moet word by ontwerp van fasilitieite. Die empiriese studie het omvattende voetganger beweging karakteristieke uitgewys wat die verhoudings tussen digtheid, spoed en vloei inkorporeer asook die effek van kultuur en ander faktore wat verband hou met die unieke konteks van die plaaslike Suid-Afrikaanse omgewing. Nuwe metodes om ruimtelike-vereistes te bepaal word voorgestel, saam met nuwe en unieke empiriese data vir gebruik deur die plaaslike industrie. ‘n Gekalibreerde en gevalideerde SP-model is ontwikkel om die ontwerp van spoorweg stasies te assesseer en word in hierdie tesis beskyf en aangebied. Die studie toon dat akkurate data en kennis oor plaaslike voetganger vloei met die SP-model verkry kan word, soos bewys uit twee spoorweg stasie studiegevalle. Die resultate van hierdie tesis dien as ‘n belangrike bydrae tot die kennis van plaaslike voetganger vloei en word geag as ‘n waardevolle hulpbron vir die ontwikkeling van voetganger modelle in die praktyk. Hierdie resultate mag nuttig wees gedurende die beplanning en ontwerp van voetganger-areas in Suid-Afrikaanse spoorweg stasies. Dit kan ook toegepas word vir spoorweg stasies in die res van Afrika wat soortgelyke voetganger karaktereienskappe het. Die navorsing het daarin geslaag om die benadering tot spoorweg stasie ontwerp te verbeter, asook om empiriese data, kennis en die metodes wat binne die plaaslike ingenieurs industrie voorgehou word, te verbeter. Let egter daarop dat die bydrae wat hierdie tesis maak, asook bydraes deur relevante konferensie verhandelinge, ‘n vroeë stap is in die verandering van persepsies in Suid-Afrika om geskikte prestasie-gebaseerde ruimte ontwerpe te verseker.

碩士
建國科技大學
電機工程系暨研究所
104
The purpose of this paper is to study a control equipment of energy-saving and time-saving about traffic flow. The research object included two sets of vehicle guiding device and two sets of traffic signs display units. Two sets of vehicle sensors are installed on the car route and mainly sense the amount of vehicles which are waiting for the red light on the road. The device contains a control core as the programmable logic controller and a set of power applying mode to provide the power of all controlling units. The operation principle is to sense the amount of waiting vehicles on the road via the two sets of vehicle sensors. The two sets of sensors finish the arithmetic operation after sensing the amount of traffic flow and then transmit to the programmable logic controller. The traffic light will decide to extend or shorten the seconds of red or green signals via the controller. Therefore, this controlling device can actually and instantly evacuate traffic jam and reduce the waiting time of vehicles. Meanwhile, it also cut down the wasting of fuel consumption and air pollution.

碩士
國立臺灣大學
土木工程學研究所
100
Mixed traffic flow is the most common traffic situation in urban roads in Taiwan. The interaction between cars and motorcycles is regarded as the most complex traffic topic in Taiwan; therefore it’s also a difficult problem in Microscopic Traffic simulation. To completely resolve this issue, it is necessary to construct a probabilistic car-following model, which is a set of microscopic simulation software. The first step is to make a detailed analysis to find out the characteristics of mixed traffic flow, then to build the probabilistic car-following model of different vehicle types. In this study, the selection is the west-bound of Section 4, Chung Hsiao East Road, Taipei, with typically mixed traffic flow characteristics. The length is about 350 m. The microscopic traffic flow data is obtained by Investigation and screening of the video recorded by DV installed on the top of high-rising buildings in the morning rush hours. By analyzing a lot of video records of the motorcycles which follow cars in the selected lane, this study found that the lateral offset could result the vertical spacing and the time headway to be smaller; and found that there are a lot of variability on the driver’s following behavior. This study is a new introduction of the Markov model in mixed traffic environment, together with the probability for random conditions. To simulate a driver’s following behavior with the conditions (speed, lateral offset, time headway) under a moment of the probability of the new decision-making speed, combined with the perception of the boundaries of the behavior threshold model, promptly driving in a perception among various acceleration or deceleration models. This study also introduces a lateral offset variable on the behavior of the threshold model making it a three-dimensional variable following model (longitudinal spacing, lateral spacing and speed difference), being more suitable for mixed traffic flow.

碩士
國立交通大學
交通運輸研究所
92
Riders have to mention the acceleration, deceleration and changes of the displacement directions of themselves when they enter the approach of general signalized intersections. Because there is no exact rule of moving direction on the middle of intersection, and the high mobility of motorcycles, and riders usually try to find the shortest path, motorcycles become the cause of the disorder on the intersections and approaches. The basic solution of this problem is to dredge the flow of motorcycles across the intersection smoothly. In this study, we proceed to analyze the departure characteristics of the motorcycles and derive the departure rate of motorcycles and its model, then discuss the reason why motorcycles become the cause of disorders on the intersections from the outcome of the model and the effect of factors, and bring up the suggestion of improvement. In this study, we proceed to video investigation, models construction, and the outcome of variables and models comparison. We confirm that the departure rate of motorcycles would rise to the top from 2 to 4 seconds after the beginning of green light. After that, it would fall down until 20 to 40 seconds after the beginning of green. When the motorcycles upstream arrive, the departure rate would rise a little until the green light ends. We can also separate the three parts from the 2-second departure rate figures. We proceed to construct the departure rate model and separate the queue of motorcycle to two parts—front-queue and back-queue. There are three final models at both intersections, including the motorcycle departure rate model of front-queue, the model of back-queue at SinYi - FuSing intersection, and the model of back-queue at ZhongSiao - Fusing intersection. Those can be useful to predict the motorcycle queue departure rate at similar intersections. We continue to analyze the application of effective factors. And consider that management enhancing and preventing drivers against traffic regulations in crossing are the first thing we should do to improve the traffic at rush hours on Zhong - Siao intersection.

碩士
國立交通大學
運輸科技與管理學系
101
Mild gradient leads to the capacity reduction in some sections of the freeways, even forms a bottleneck. Setting up an auxiliary sign to recommend drivers to accelerate while passing the mild gradient is a common treatment in Taiwan for the past few years to reduce the speed drop and narrow the speed differential. This study aims to investigate whether drivers will receive the information and accelerate while passing the mild gradient to improve the capacity. The results find that after setting up auxiliary signs, the speed differential is lower in all traffic lanes. But the average speed is lower than before in overtaking lane and outside lane, leading to an average speed reduction in this experiment section. The mileage production of the overtaking lane and the outside lane are also decreased. In conclusion, the transportation ability of this section is not improved after installing the auxiliary signs. However, it should be noted that the traffic volume had increased 15% over the study period. It might cause the speed reduction and dilute the effects from these auxiliary signs.

碩士
國立成功大學
環境工程學系碩博士班
94
The main idea of this research is to measure gaseous pollutant, particles, and flow of vehicles in tunnels, and to calculate emission factors of different kind of vehicles with data collected in tunnel sampling. In order to get emission factors of different kind of vehicles, we chose Don-Men tunnel in Tainan city for motorcycles, and Chung-Liau tunnel in southern 2nd expressway for LDV and HDV(light-duty vehicles and heavy-duty vehicles)as our experiment spots. 　We found that the concentration of particles is up to 1.8×109count/m3; concentration of CO is 46.4ppm as highest inside the Don-Men tunnel. The characteristic nano-particle size emitted by motorcycles lays on 28.5 and 56.2 nm. The emission factor of CO, CO2, NO, and SO2 are 5.17±1.62, 109.76±10.11, 0.05±0.01, 0.006±0.003 g/km respectively. We calculated fuel-based emission factors as well. The results are 1.25±0.40, 0.15±0.07 g/kg-fuel with NO, SO2 respectively. 　We also found the highest concentration of particles inside Chung-Liau tunnel is 3.0×108count/m3. After separating data measured by SMPS, we got three characteristic peak. The mean of them are 21.6nm, 11nm and 68.4nm respectively. Because of the ventilation system, condition of diffusion, and the assumption we made as we calculated emission factors are not too match with truth, we got bad results. They are much different from data listed by other researches before.

Cette thèse porte sur la modélisation du trafic dans les réseaux routiers et comment celle-ci est intégrée dans des modèles d'optimisation. Ces deux sujets ont évolué de manière plutôt disjointe: le trafic est prédit par des modèles mathématiques de plus en plus complexes, mais ce progrès n'a pas été incorporé dans les modèles de design de réseau dans lesquels les usagers de la route jouent un rôle crucial. Le but de cet ouvrage est d'intégrer des modèles d'utilités aléatoires calibrés avec de vraies données dans certains modèles biniveaux d'optimisation et ce, par une décomposition de Benders efficace. Cette décomposition particulière s'avère être généralisable par rapport à une grande classe de problèmes communs dans la litérature et permet d'en résoudre des exemples de grande taille. Le premier article présente une méthodologie générale pour utiliser des données GPS d'une flotte de véhicules afin d'estimer les paramètres d'un modèle de demande dit recursive logit. Les traces GPS sont d'abord associées aux liens d'un réseau à l'aide d'un algorithme tenant compte de plusieurs facteurs. Les chemins formés par ces suites de liens et leurs caractéristiques sont utilisés afin d'estimer les paramètres d'un modèle de choix. Ces paramètres représentent la perception qu'ont les usagers de chacune de ces caractéristiques par rapport au choix de leur chemin. Les données utilisées dans cet article proviennent des véhicules appartenant à plusieurs compagnies de transport opérant principalement dans la région de Montréal. Le deuxième article aborde l'intégration d'un modèle de choix de chemin avec utilités aléatoires dans une nouvelle formulation biniveau pour le problème de capture de flot de trafic. Le modèle proposé permet de représenter différents comportements des usagers par rapport à leur choix de chemin en définissant les utilités d'arcs appropriées. Ces utilités sont stochastiques ce qui contribue d'autant plus à capturer un comportement réaliste des usagers. Le modèle biniveau est rendu linéaire à travers l'ajout d'un terme lagrangien basé sur la dualité forte et ceci mène à une décomposition de Benders particulièrement efficace. Les expériences numériques sont principalement menés sur un réseau représentant la ville de Winnipeg ce qui démontre la possibilité de résoudre des problèmes de taille relativement grande. Le troisième article démontre que l'approche du second article peut s'appliquer à une forme particulière de modèles biniveaux qui comprennent plusieurs problèmes différents. La décomposition est d'abord présentée dans un cadre général, puis dans un contexte où le second niveau du modèle biniveau est un problème de plus courts chemins. Afin d'établir que ce contexte inclut plusieurs applications, deux applications distinctes sont adaptées à la forme requise: le transport de matières dangeureuses et la capture de flot de trafic déterministe. Une troisième application, la conception et l'établissement de prix de réseau simultanés, est aussi présentée de manière similaire à l'Annexe B de cette thèse.
The subject of this thesis is the modeling of traffic in road networks and its integration in optimization models. In the literature, these two topics have to a large extent evolved independently: traffic is predicted more accurately by increasingly complex mathematical models, but this progress has not been incorporated in network design models where road users play a crucial role. The goal of this work is to integrate random utility models calibrated with real data into bilevel optimization models through an efficient Benders decomposition. This particular decomposition generalizes to a wide class of problems commonly found in the literature and can be used to solved large-scale instances. The first article presents a general methodology to use GPS data gathered from a fleet of vehicles to estimate the parameters of a recursive logit demand model. The GPS traces are first matched to the arcs of a network through an algorithm taking into account various factors. The paths resulting from these sequences of arcs, along with their characteristics, are used to estimate parameters of a choice model. The parameters represent users' perception of each of these characteristics in regards to their path choice behaviour. The data used in this article comes from trucks used by a number of transportation companies operating mainly in the Montreal region. The second article addresses the integration of a random utility maximization model in a new bilevel formulation for the general flow capture problem. The proposed model allows for a representation of different user behaviors in regards to their path choice by defining appropriate arc utilities. These arc utilities are stochastic which further contributes in capturing real user behavior. This bilevel model is linearized through the inclusion of a Lagrangian term based on strong duality which paves the way for a particularly efficient Benders decomposition. The numerical experiments are mostly conducted on a network representing the city of Winnipeg which demonstrates the ability to solve problems of a relatively large size. The third article illustrates how the approach used in the second article can be generalized to a particular form of bilevel models which encompasses many different problems. The decomposition is first presented in a general setting and subsequently in a context where the lower level of the bilevel model is a shortest path problem. In order to demonstrate that this form is general, two distinct applications are adapted to fit the required form: hazmat transportation network design and general flow capture. A third application, joint network design and pricing, is also similarly explored in Appendix B of this thesis.

This research work is focused on understanding the effects of inhomogeneity on traffic flow by theoretical analysis and computer simulations. Traffic has been observed at almost all levels of natural and manmade systems (e.g., from microscopic protein motors to macroscopic objects like cars). For these various traffic, basic and emer- gent phenomena, modelling methods, theoretical analysis and physical meanings are normally concerned. Inhomogeneity like bottlenecks may cause traffic congestions or motor protein crowding. The crowded protein motors may lead to some human diseases. The congested traffic patterns have not been understood well so far. The modelling method in this research is based on totally asymmetric simple exclusion process (TASEP). The following TASEP models are developed: TASEP with single inhomogeneity, TASEP with zoned inhomogeneity, TASEP with junction, TASEP with site sharing and different boundary conditions. These models are motivated by vehicular traffic, pedestrian trafficc, ant traffic, protein motor traffic and/or Internet traffic. Theoretical solutions for the proposed models are obtained and verified by Monte Carlo simulations. These theoretical results can be used as a base for further developments. The emergent properties such as phase transitions, phase separations and spontaneous symmetry breaking are observed and discussed. This study has contributed to a deeper understanding of generic traffic dynamics, particularly, in the presence of inhomogeneity, and has important implications for explanation or guidance of future traffic studies.

Indiana University-Purdue University Indianapolis (IUPUI)
Pedestrian and vehicle interaction analysis in a naturalistic driving environment can provide useful information for designing vehicle-pedestrian crash warning/mitigation systems. Many researchers have used crash data to understand and study pedestrian behaviors and interactions between vehicles and pedestrian during crash. However, crash data may not provide detailed pedestrian-vehicle interaction information for us. In this thesis, we designed an automatic pedestrian tracking and status analysis method to process and study pedestrian and vehicle interactions. The proposed pedestrian tracking and status analysis method includes pedestrian detection, pedestrian tracking and pedestrian status analysis modules. The main contributions of this thesis are: we designed a new pedestrian tracking method by learning the pedestrian appearance and also their motion pattern. We designed a pedestrian status estimation method by using our tracking results and thus helped estimate the possibility of collision. Our preliminary experiment results using naturalistic driving data showed promising results.

Research Doctorate - Doctorate of Business Administration (DBA)
Government mandated institutions in Australia and Canada have continuously progressed banking regulation throughout time by making gradual alterations to prudential frameworks and supervisory practices. This has included the prompt domestic adaptation of the three Basel accords. A main objective is to ensure banking organisations become more resilient to stresses that impact their capital and liquidity adequacy. Banking organisations are faced with the task of transforming their balance sheets and funding profiles to not only strengthen their balance sheets but to curb heighted liquidity costs that have been brought on by regulatory reform. A review of existing literature on the components of bank funding, liquidity and procyclicality recognises their significance in ensuring individual bank stability and the prevarication of broader systemic implications in the wider economy. This dissertation has examined the historical evolution of the regulatory environments in both Australia and Canada and compared the components of bank balance sheets that offer insights into their funding preference and liquidity holdings, and provide early indicators for procyclicality within the banking sector. It has also had the goal of developing existing research and knowledge of liquidity stresses within bank balance sheets. This research has endeavoured to further balance sheet innovation, through action research that has been carried out over a five year period, to provide banking organisations with options to alter their balance sheets in order to meet the Basel III package of reforms and better deal with liquidity pressures, such as those that were evident in many countries throughout the most recent financial crisis. A new methodology for balance sheet transformation under Basel III, “evergreen” is articulated, with a suite of evergreen asset and liability products and balance sheet exposures being assessed for impact and acceptance within the banking industry. Verification of the evergreen method is demonstrated by the banking industry including it within their strategy for future balance sheet innovation; banks designing and constructing evergreen capability; the regulator encompassing it within prudential standards; and widespread acceptance of evergreen by investors and other financial market participants. Whilst components of evergreen are increasingly becoming a greater part of the banking industry within Australia, it is recognised that the concepts and models of evergreen, are at a primary juncture in their development and require substantial additional focus and research. The usefulness of this dissertation will be established through the particulars of future research settings and must be appraised to the degree that it appears correct, original and apt. Regarding deposits, this dissertation finds that: the existence of voluntary deposit insurance schemes would allow the competitive landscape for retail deposits to become about more than just price; operational deposits are not immune from procyclical competition; Australian banks have a much greater appetite and tolerance for at-call deposit raising; liquidity regulation has permanently shifted the ‘market rate’ for deposit funding above its ‘natural rate’; and foreign currency deposit raising may lead to banks running unhedged positions or developing a larger reliance towards United States Dollars. For wholesale funding, it is observed that: liquidity regulation has increased the reliance of banks on domestic financial markets to fulfil their financing needs; the volume of short-dated prime bank paper being issued in Australia has declined where there are consequences for the Bank Bill Swap Rates; and large differentials in the semi/quarterly spread can substantially impact the profitability of banking book products. The domestic implementation of the Basel III package of reforms on liquidity in both Australia and Canada has, in many ways, imitated the historical approach taken towards bank capital regulation. This dissertation deducts that, as there is for capital, the concept of ‘regulatory’ and ’economic’ liquidity now exists. Furthermore, regulation has introduced a predisposition to government bonds, which may have unintended consequences for both government sponsored issuers and bank investors. Finally, procyclicality must be monitored and managed by the government sponsored institution tasked with the role of implementing monetary policy, rather than institutions that implement and enforce prudential regulation.