Equilibria on a congested transportation network

Bibliography: leaves 26-29.Supported in part by the Transportation Advanced Research Program of the U.S. Department of Transportation under contract. DOT-TSC-1058 Supported in part by the National Science Foundation under grant. 79-26225-ECSby Hedayat Z. Aashtiani and Thomas L. Magnanti

Framework for integrated planning of bus and paratransit services in Indian cities

Public transport services in India and many other developing countries are provided by a combination of formal-Government led public transport systems and informal paratransit or Intermediate Public Transport (IPT) systems, which offer shuttle services along high demand corridors with passengers boarding and alighting at multiple points. Despite limited Government support, paratransit systems continue to thrive in many cities serving a crucial shared mobility need of users, without which cities would have more private vehicle usage. Due to their informal nature and the perceived competition to formal public transport systems, they have traditionally been either excluded from the public transport planning processes or designed as a feeder service to the formal transit system. The current thesis recognises paratransit’s role in serving end to end travel demand needs, particularly in developing economies with limited public transport supply and not just being a feeder to the formal public transport system. Hence, we develop an integrated planning framework that enables formal and informal public transport systems to operate as complementary systems towards meeting the mobility needs of the city. We proved an integrated planning framework based on comprehensive understanding of the demand and supply characteristics of both formal and informal systems which currently operate independently to realign services and complement each other. The tactical planning stage of public transport planning i.e. frequency setting was identified as the ideal stage of planning for integration of the two types of services. This will ensure continuity of their existing route networks and at the same time allow for paratransit services’ flexibility to switch operations between routes. Visakhapatnam, a representative medium sized Indian city with a significant presence of formal public transport in the form of city bus services and paratransit services provided by three-wheeler auto-rickshaws with a seating capacity of three to six passengers, was selected as the case city to demonstrate the methodology. A household survey based data collection and analysis methodology was adopted to analyse the socio-economic and travel demand characteristics of city bus and paratransit users. The variables impacting users’ choice between these two systems were derived through binary logistic regression. The high frequency and low occupancy paratransit systems were more popular among shorter trips, while longer trips preferred the fixed table bus systems. The operational characteristics of bus and paratransit systems were derived through a combination of primary surveys with paratransit operators and secondary data on the city bus operations. Data regarding their network of operation, services offered, passenger demand and revenue generated were collected for analysis. Buses perform a service function in the city by operating throughout the day and on a wider network, while paratransit operates with a profit motive only on high demand corridors and during peak hours. A Data Envelopment Analysis (DEA) based methodology was adopted to compare the performance efficiency of the two systems using a set of input and output indicators that define the performance of the two systems. Paratransit operations were identified to be more efficient compared to buses, due to their demand responsive operations. The lower efficiency of buses was also due to their service obligation to the city to provide affordable services throughout the day, even in areas with low demand. A bi-level transit assignment and frequency optimisation framework is developed to integrate formal bus and paratransit services. The lower-level of the model solves for the multi- modal transit assignment problem while the upper level solves for the integrated frequency optimisation problem. The transit assignment problem was solved from the users perspective i.e. to minimise their travel time through the user-equilibrium method. The frequency optimisation problem was solved using an integer programming formulation with the objective of minimising operational cost of bus and paratransit systems while meeting constraints like the travel demand on any link. The outputs from the optimisation exercise were used to quantify the impact of the public transport system at various levels i.e. users total travel time spent in the system, operators cost of providing the services and the overall impact on the society by estimating its road space requirement and emissions. Alternative user demand and transit supply scenarios were tested to assess their impacts on the society. The results show significant operational cost benefits of an integrated transit assignment and frequency planning approach where paratransit provides demand responsive services for short distance trips while formal public transport provides fixed schedule services on with broader network coverage. The analysis established the complimentary role played by bus and paratransit systems in meeting users travel demands. Therefore, it is recommended that cities harness both the systems towards meeting increasing travel needs of developing economies. Formal transit will continue to be the core of the public transport system, providing fixed route services, while paratransit can augment its capacity on high demand corridors and during peak hours. The planning and frequency optimisation framework developed in this thesis can help cities in identifying the modal-mix of fixed route public transport and on-demand services

Kelionių grandinėmis pagrįsto susisiekimo poreikių modelio kūrimas ir taikymas miestų susisiekimo tinklo planavimui

This thesis is devoted to the analysis of the advanced and innovative tour-based travel demand modelling approach. Tour-based models explicitly recognise traffic as a derived demand for undertaking activities between homes and destinations. Travel demand of urban residents is modelled as trip sequences, which allows precise modelling of trip origin and destination points. The tour-based approach is deemed as a key step forwards towards even more complex agent-based modelling systems. The thesis is structured around three main chapters that can be summarised succinctly as a revision of the state of the practice and research, description of empirical research of travel behaviour, and tour-based model development. The 1st chapter revises the current state of practice and the research on travel demand modelling. All the building blocks that comprise transport models are discussed, and this lays the theoretical foundation for the following chapters. 1st chapter also gives a thorough comparison of trip-based and tour-based model-ling approaches and presents modelling environment. The 2nd chapter defines the process of conducting an empirical research of the travel behaviour patterns of urban residents. The 2nd chapter defines survey methodology and important mobility parameters such as activity sequences and their probabilities of homogeneous urban population segments. The outputs from the 2nd chapter are not only important and interesting on their own, but they also flow into the final third part of the work. The final 3rd chapter defines tour-based travel demand model development steps and showcases their practical application to the real-world scenario. Demand model quality assessment efforts and results are presented and discussed together with necessary explanations for significant deviations from reality. The resulting model is applied to investigate the performance of Siaurine Street in Vilnius, which is to be built in the coming years. At the very end of 3rd chapter a compre-hensive urban travel demand modelling framework is formulated and serves as a best practice guide. General conclusions summarises the whole study. These are followed by an extensive list of references that were mentioned or relied upon to some extent in the work. Finally, separate lists of scientific publications and conference presen-tations conclude the thesis. Overall, there have been five scientific articles published on the topic of the thesis. Four articles were published in scientific journals that are referenced in Clarivate Analytics Web of Science database, and one article was published in a scientific journal that is referenced in other databases

Time-dependent discrete network design frameworks considering land use

This article proposes optimization frameworks for discrete road network design considering the land-use transport interaction over time. Unlike existing models, the optimization frameworks can determine the optimal designs automatically without trial-and-error once the objective(s) is/are clearly defined. Moreover, these frameworks allow the evaluation of the impacts of the optimal designs on the related parties including landowners, toll road operators, transit operators, and road users, and help network planners and profit-makers with decision making by eliminating many alternative designs. A numerical study is set up to examine road network design's effects on these related parties under three road construction schemes: exact cost recovery, build-operate-transfer, and cross-subsidization. The results show that the changes in landowner profits are not the same after implementing any scheme. These unequal changes raise the issue of the landowner equity. This implies that the government has to consider trade-offs between parties' objectives carefully. © 2010 Computer-Aided Civil and Infrastructure Engineering.postprin

Modeling and estimating the capacity of urban transportation network with rapid transit

To study the impact of the rapid transit on the capacity of current urban transportation system, a two-mode network capacity model, including the travel modes of automobile and transit, is developed based on the well-known road network capacity model. It considers that the travel demand accompanying with the regional development will increase in a variable manner on the trip distribution, of which the travel behavior is represented using the combined model split/trip distribution/traffic assignment model. Additionally, the choices of the travel routes, trip destinations and travel modes are formulated as a hierarchical logit model. Using this combined travel demand model in the lower level, the network capacity problem is formulated as a bi-level programming problem. The latest technique of sensitivity analysis is employed for the solution of the bi-level problem in a heuristic search. Numerical computations are demonstrated on an example network, and the before-and-after comparisons of building the new transit lines on the integrated transportation network are shown by the results

Intermodal commuter network planning

An intermodal commuter network is an integration of passenger transportation systems, or modes, to a single comprehensive system that provides connections among the various modes, and improved travel choices to users. In the system examined in this dissertation, commuters access their final destination via auto, rail, and intermodal auto-to-rail modes. There are numerous highway paths by which a commuter can reach the final destination. Once on the highway, the commuter can switch to rail at stations along the rail route. The commuter may also choose to walk to the rail station closest to the trip\u27s origin. The main focus of this dissertation is the development of models that can estimate traffic volumes and travel costs on intermodal networks. The particular approach used in the models is demand and supply equilibrium where transportation flows are impacted by the performance of the transportation facilities. Several optimization models are formulated based on sound mathematical and economic principles, and their equilibrium conditions are derived and stated clearly. A rigorous analysis of the mathematical properties of the models proves that these conditions are satisfied from the model solutions. The objective of these models is to alleviate some of the deficiencies encountered in the urban transportation planning process. A methodological framework is proposed which utilizes the models to analyze and evaluate operating and pricing policies in intermodal networks. The framework is designed to answer questions of interest to transportation planners, and to investigate the trade-offs between reduction in travel time and the increased cost of capacity improvements. To link theory and practice, the models are applied, within the proposed framework, to the analysis of a real-world intermodal commuter network. Policies aimed at improving the service quality of the intermodal network are evaluated based on their benefits compared to existing conditions. The models are also used to design an optimal rail transit service by computing rail fares and headways to meet future demands. The results of the analysis can be used by transportation planners, decision makers, transit operators, and transportation system managers to find effective ways to alleviate congestion on transportation systems. To this end, this dissertation points to areas of future research to further improve the proposed models

A continuous model for coordinated pricing of mixed access modes to transit

The land-use pattern for many cities is a central business district surrounded by sprawling suburbs. This pattern can lead to an inefficient and congestion-prone transportation system due to a reliance on automobiles. This is because high-capacity transit is inefficient in low-density areas where insufficient travelers can access transit. This also poses an equity concern as the monetary cost of faster and more expensive travel disproportionately burdens low income travelers, especially when fixed congestion pricing is imposed. This paper presents a deterministic approximation of a discrete choice model for mixed access and mainline transportation modes, meaning that travelers may use different modes to access a mainline system, such as transit. The purpose is to provide a tractable computationally efficient model to address the first/last mile problem using a system-wide pricing policy that can account for heterogeneous values of time; a problem that is difficult to solve efficiently using a stochastic model. The model is structured for a catchment area around a central access point for a mainline mode, approximating choice by comparing modal utility costs. The underlying utility model accommodates both fixed prices (e.g., parking, fixed tolls, and fares) and distance-based unit prices (e.g. taxi fare, bike-share, and distance tolls) that may be set in a coordinated way with respect to value of time. Using numerical analysis to assess accuracy, the deterministic model achieved results within 3% of a stochastic logit-based model, and within 7% of measured values. The optimization of prices using the final model achieved a 22% reduction in generalized travel time and a 30% improvement in the Gini inequity measure from 0.2 to 0.14

The design of public transit networks with heuristic algorithms : case study Cape Town

Includes bibliographical references.The Transit Network Design Problem (TNDP) is well-researched in the field of transportation planning. It deals with the design of optimized public transportation networks and systems, and belongs to the class of non-linear optimization problems. In solving the problem, attempts are made to balance the tradeoffs between utility maximization and cost minimization given some resource constraints, within the context of a transportation network. In this dissertation, the design of a public transit network is undertaken and tested for Cape Town. The focus of the research is on obtaining an optimal network configuration that minimizes cost for both users and operators of the network. In doing so, heuristic solution algorithms are implemented in the design process, since they are known to generate better results for non-linear optimization problems than analytical ones. This algorithm which is named a Bus Route Network Design Algorithm (BRNDA) is based on genetic algorithms. Furthermore, it has three key components namely: 1) Bus Route Network Generation Algorithm (BRNGA) - which generates the potential network solutions; 2) Bus Route Network Analysis Procedure (BRNAP) - which evaluates the generated solutions; 3) Bus Route Network Search Algorithm (BRNSA) - which searches for an optimal or near optimal network option, among the feasible ones. The solution approach is tested first on a small scale network to demonstrate its numerical results, then it is applied to a large scale network, namely the Cape Town road network

A model for land use and freight transportation coordination in Shanghai, China

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal