The Americans with Disabilities Act of 1990 (ADA) stipulates the provision of complementary paratransit to people unable to use regular public transportation. With the emergence of a wide range of public transportation services, problems have occurred for public transit agencies, especially the rising costs of providing services for paratransit. Even though paratransit services are one of the most efficient ways to help move people with disabilities and the elderly, they are the most expensive and the most difficult to coordinate and operate. The purpose of this thesis is to define different types of paratransit services and their characteristics, expound major paratransit expense issues, describe the existing conditions of paratransit in Richmond, Virginia, and make policy and strategy recommendations for the Greater Richmond Transit Company (GRTC) based on a comparative analysis of fifteen case studies of paratransit agencies in the country.

Traditional public transport systems are most often insufficient to provide a good transport service to everyone. Especially, it is not always possible for elderly and disabled persons to use the regular system consisting of timetabled services operating along fixed routes. Normally there is some specific service, often called paratransit, offered to these groups of customers. Such transport services provide better service to these customers, but to a higher cost. This thesis considers planning and evaluation of public transport services that are based on the concept of a dial-a-ride service. This kind of service is suitable for elderly and disabled and often operated as a door-to-door service, where customers are served on demand and rides are coordinated via a call-center. The thesis is divided into two parts. In the first part, a modeling system for simulation of dial-a-ride services is presented. It can be used as a tool to study how different ways of operating a dial-a-ride service, affect the performance and efficiency of the service. This system is used to evaluate how algorithmic changes, based on ruin-and-recreate methods, can improve the replanning of already inserted requests, and thereby improve the scheduling. The modeling system is also used to examine the effects of using zone-based distance estimates instead of true, address-based, distances when computing the schedules. The results show that only small differences are found.The second part of the thesis concerns an extension to dial-a-ride services. By combining a dial-a-ride service with a fixed route service, an integrated dial-a-ride service is created, where some part of each journey may be carried out by the fixed route service. An exact mathematical formulation of this problem is presented and it is shown that the formulation is strengthened by valid inequalities, variable substitution and subtour elimination constraints. Simulations of an integrated service are also performed to analyze and evaluate how the attractiveness and operating costs of the service depend on how the demand responsive service is operated.

Despite the continued interest in transportation accessibility, it is still unclear how different types of accessibility measures relate to one another and which situations are best for each. The current study undertakes a statistical comparison among six transit accessibility measures (representing three main categories of accessibility models) to determine whether they are comparable and/or interchangeable. Specifically, this analysis considers a case study to measure individuals’ access to healthcare via paratransit. Results indicate that the three categories of accessibility measures provide drastically different interpretations of accessibility that cannot be duplicated by each other. Furthermore, the more closely accessibility models capture individuals’ perceptions and true access to activity opportunities, the more consistent and evenly distributed the results. / text

Thesis (Ph.D.)(Industrial Engineering)--University of Pretoria, 2006. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

Dans le contexte du développement rapide des villes chinoises, l’expansion de la ville et les nouvelles zones de développement entraînent de forte besoins de mobilité. Le transport public ne peut satisfaire toutes les demandes des déplacements des citadins. Ils organisent leurs propres services, les transports semi-collectifs, par une approche de bas en haut. Avec les avantages de l’adaptation locale, du service à la demande et de la flexibilité, ce type de transport devient un mode important pour leurs vies moderne. Pourtant, ce transport est en dehors du système du transport traditionnel. Le cadre juridique et institutionnel actuel n’est pas adapté à l’exploitation de ces transports spontanés. La réglementation gouvernementale sur ce type de transport montre aussi une difficulté en raison du manque d’un cadre convenable. De plus, le système du transport urbain durable demande une intégration des divers modes des transports. La relation entre le transport semi-collectif et les autres moyens du transport devient une question essentielle. De ce fait, nous proposons des approches de l’évolution du cadre juridique et institutionnel, de l’amélioration de l’organisation et l’exploitation ainsi que de l’intégration dans le système du transport urbain, afin de créer un environnement innovant pour l’avenir du transport semi-collectif / In the context of the rapid development of Chinese cities, the expansion of the city and the new areas of developments lead the strong mobility needs. Public transport cannot meet all the demands of movement of citizens. They organize their own services, paratransit, with an approach bottom-up. With the advantages of local adaptation, on-demand service and flexibility, this transport becomes important to their modern lives. However, this transport is out of the traditional transport system. The current legal and institutional framework is not suitable for the operation of this spontaneous transport. Government regulations on this type of transport also show difficult because of lack of suitable frames. In addition, the sustainable urban transport system requires integration of various modes of transport. The relationship between the paratransit and other transportation modes is another key issue. Therefore, we propose approaches to change legal and institutional framework, to improve organization and operation and integrate this mode in the system of urban transport, to create an innovative environment for future of paratransit

published_or_final_version / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

This study concerns paratransit service in a relatively small municipality in Sweden. The aim of this study is to describe the user's experience of paratransit service. The question formulation is mainly built around the user's experience of paratransit service and their view on what impact paratransit service has on their lives. The empirical data consists of ten interviews with ten different paratransit service users with ages ranging from 25-95 years. The data has mainly been analyzed through concepts of independence, empowerment and trust.The result of this study shows that paratransit service in many ways can be described as a crucial part of the users' lives. The result also shows that paratransit service generates a sense of independence in many ways, enabling the user to carry on with their daily lives, visit friends, work etc. In this way paratransit service can be understood in terms of empowerment as a way to prevent social isolation. At the same time the user is dependent on the rules of the paratransit service organization mainly because there are no other options of transportation for the user. The user's relationship with the paratransit service raises several questions concerning trust. The question of trust mainly relates to the relationship between the user and the driver. The study shows that trust is a key factor for the user's feeling of security.

South Africa provides a fascinating interface between the developed and the developing world and poses a multitude of opportunities for enhancing the sustainable development of local cities. The concept of City Logistics is concerned with the mobility of cities, and entails the process of optimizing urban logistics activities by considering the social, environmental, economic, financial, and energy impacts of urban freight movement. Vehicle routing and scheduling has the potential to address a number of these key focus areas. Applying optimization to vehicle routing and scheduling results in a reduced number of trips, better fleet utilization, and lower maintenance costs; thereby improving the financial situation of the fleet owner. Improved fleet utilization could have a positive environmental impact, while also improving the mobility of the city as a whole. Energy utilization is improved while customer satisfaction could also increase through on-time deliveries and reliability. The Vehicle Routing Problem (VRP) is a well-researched problem in Operations Research literature. The main objective of this type of problem is to minimize an objective function, typically distribution cost for individual carriers. The area of application is wide, and specific variants of the VRP transform the basic problem to conform to application specific requirements. It is the view of this dissertation that the various VRP variants have been researched in isolation, with little effort to integrate various problem variants into an instance that is more appropriate to the South African particularity with regards to logistics and vehicle routing. Finding a feasible, and integrated initial solution to a hard problem is the first step in addressing the scheduling issue. This dissertation attempts to integrate three specific variants: multiple time windows, a heterogeneous fleet, and double scheduling. As the problem is burdened with the added constraints, the computational effort required to find a solution increases. The dissertation therefore also contributes to reducing the computational burden by proposing a concept referred to as time window compatibility to intelligently evaluate the insertion of customers on positions within routes. The initial solution algorithm presented proved feasible for the integration of the variants, while the time window compatibility decreased the computational burden by 25%, and as much as 80% for specific customer configurations, when using benchmark data sets from literature. The dissertation also improved the quality of the initial solution, for example total distance traveled, by 13%. Finding an initial solution is the first step in solving vehicle routing problems. The second step is to improve the initial solution iteratively through an improvement heuristic in an attempt to find a global optimum. Although the improvement heuristic falls outside the scope of this dissertation, improvement of the initial solution has a significant impact on the quality of improvement heuristics, and is therefore a valuable contribution. / Dissertation (MEng)--University of Pretoria, 2007. / Industrial and Systems Engineering / MEng / Unrestricted