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Within transport planning, accessibility is generally defined as the ease with which people from specific locations can travel to participate in activities using a mode of transport. The problem with most measures of accessibility is that they lack the capability to evaluate the impacts of transport policies that can directly influence travel decisions. / There is a need for measures of accessibility to be more sensitive to transport policies. This thesis discusses a framework used to develop measures of accessibility that take into consideration the travel behaviour of individuals and other factors that are sensitive to transport and urban planning policies. Such measures provide a valuable tool for transport and urban planners to evaluate both physical improvements to transport networks and the comparison of policies in terms of their relative cost of implementation, usefulness, efficiency and effectiveness. / In addition, this thesis argues that accessibility is more than just overcoming spatial separation between locations. It acknowledges the differences between individuals for whom the measures are calculated, the activities to which individuals need access, the properties of the locations of activities, the transport system that facilitates travel to overcome the separation between individuals and activities, and the effects of available time on accessibility. / Accessibility measures are commonly trip-based as they consider the accessibility from one location to another. Although the trip-based concept is important and useful in transport planning, there is also a need for an activity-based measure of accessibility that focuses on accessibility of people to activities rather than just accessibility between locations. / The accessibility framework is based on travel information collected through travel diaries that indicate the travel patterns of individuals within households. The thesis reports on how such information was used to develop behavioural models to reflect travel decisions by individuals. The behavioural-based measures provide a technique to determine the influence of factors on accessibility and ensure measures of accessibility to be dissected to enable the various components of accessibility to be analysed. These measures of accessibility provide the transport or urban planner the ability to determine what affects accessibility in specific areas and test policies that may rectify the problem. / The accessibility framework was applied to describe the accessibility levels that exist within Metropolitan Adelaide and to evaluate the urban system in terms of accessibility of individuals to activities in areas. The capabilities of the accessibility framework to evaluate both transport and land-use policies aimed at improving accessibility for the people residing in Metropolitan Adelaide to the activities they wish to partake were also demonstrated. / Thesis (PhD)--University of South Australia, 2004.

abstract: Public-Private Partnerships (P3) in North America have become a trend in the past two decades and are gaining attention in the transportation industry with some large scale projects being delivered by this approach. This is due to the need for alternative funding sources for public projects and for improved efficiency of these projects in order to save time and money. Several research studies have been done, including mature markets in Europe and Australia, on the cost and schedule performance of transportation projects but no similar study has been conducted in North America. This study focuses on cost and schedule performance of twelve P3 transportation projects during their construction phase, costing over $100 million each, consisting of roads and bridges only with no signature tunnels. The P3 approach applied in this study is the Design-Build-Finance-Operate-Maintain (DBFOM) model and the results obtained are compared with similar research studies on North American Design-Build (DB) and Design-Bid-Build (DBB) projects. The schedule performance for P3 projects in this study was found to be -0.23 percent versus estimated as compared to the 4.34 percent for the DBB projects and 11.04 percent for the DB projects in the Shrestha study, indicating P3 projects are completed in less time than other methods. The cost performance in this study was 0.81 percent for the P3 projects while in the Shrestha study the average cost increase for the four DB projects was found to be 1.49 percent while for the DBB projects it was 12.71 percent, again indicating P3 projects reduce cost compared to other delivery approaches. The limited number of projects available for this study does not allow us to draw an explicit conclusion on the performance of P3s in North America but paves the way for future studies to explore more data as it becomes available. However, the results in this study show that P3 projects have good cost and schedule adherence to the contract requirements. This study gives us an initial comparison of P3 performance with the more traditional approach and shows us the empirical benefits and limitations of the P3 approach in the highway construction industry. / Dissertation/Thesis / M.S. Construction 2012

abstract: Real-time information systems are being used widely around the world to mitigate the adverse impacts of congestion and events that contribute to network delay. It is important that transportation modeling tools be able to accurately model the impacts of real-time information provision. Such planning tools allow the simulation of the impacts of various real-time information systems, and the design of traveler information systems that can minimize impacts of congestion and network disruptions. Such modeling tools would also be helpful in planning emergency response services as well as evacuation scenarios in the event of a natural disaster. Transportation modeling tools currently in use are quite limited in their ability to model the impacts of real-time information provision on travel demand and route choices. This dissertation research focuses on enhancing a previously developed integrated transportation modeling system dubbed SimTRAVEL (Simulator of Transport, Routes, Activities, Vehicles, Emissions, and Land) to incorporate capabilities that allow the simulation of the impacts of real-time traveler information systems on activity-travel demand. The first enhancement made to the SimTRAVEL framework involves the ability to reflect the effects of providing information on prevailing (as opposed to historical) network conditions on activity-travel behavior choices. In addition, the model system is enhanced to accommodate multiple user information classes (pre-trip and enroute) simultaneously. The second major contribution involves advancing the methodological framework to model enroute decision making processes where a traveler may alter his or her travel choices (such as destination choice) while enroute to an intended destination. Travelers who are provided up-to-date network information may choose to alter their destination in response to congested conditions, or completely abandon and reschedule an activity that offers some degree of flexibility. In this dissertation research, the model framework is developed and an illustrative demonstration of the capabilities of the enhanced model system is provided using a subregion of the Greater Phoenix metropolitan area in Arizona. The results show that the model is able to simulate adjustments in travel choices that may result from the introduction of real-time traveler information. The efficacy of the integrated travel model system is also demonstrated through the application of the enhanced model system to evaluate transportation policy scenarios. / Dissertation/Thesis / Doctoral Dissertation Civil and Environmental Engineering 2014

abstract: The city of Groningen in the Netherlands is often referred to as the "world cycling city" because over fifty percent of trips are made on bicycles (Van Hoven & Elzinga, 2009). On the contrary, just four percent of trips in Tempe, Arizona are on bicycles (McKenzie, 2014). Through a series of interviews and surveys, this study investigates what causes such high bicycling rates in Groningen and applies these findings to Tempe. The results suggest that Groningen experiences high bicycling rates because the city uses "carrot" and "stick" policies to encourage bicycling and discourage driving. It is therefore recommended that Tempe adopt both types of policies to raise bicycling levels. / Dissertation/Thesis / Masters Thesis Geography 2015

abstract: Traffic congestion is a major externality in modern transportation systems with negative economic, environmental and social impacts. Freeway bottlenecks are one of the key elements besides the demand for travel by automobiles that determine the extent of congestion. The primary objective of this research is to provide a better understanding of factors for variations in bottleneck discharge rates. Specifically this research seeks to (i) develop a methodology comparable to the rigorous methods to identify bottlenecks and measure capacity drop and its temporal (day to day) variations in a region, (ii) understand the variations in discharge rate of a freeway weaving bottleneck with a HOV lane and (iii) understand the relationship between lane flow distribution and discharge rate on a weaving bottleneck resulted from a lane drop and a busy off-ramp. In this research, a methodology has been developed to de-noise raw data using Discrete Wavelet Transforms (DWT). The de-noised data is then used to precisely identify bottleneck activation and deactivation times, and measure pre-congestion and congestion flows using Continuous Wavelet Transforms (CWT). To this end a methodology which could be used efficiently to identify and analyze freeway bottlenecks in a region in a consistent, reproducible manner was developed. Using this methodology, 23 bottlenecks have been identified in the Phoenix metropolitan region, some of which result in long queues and large delays during rush-hour periods. A study of variations in discharge rate of a freeway weaving bottleneck with a HOV lane showed that the bottleneck discharge rate diminished by 3-25% upon queue formations, however, the discharge rate recovered shortly thereafter upon high-occupancy-vehicle (HOV) lane activation and HOV lane flow distribution (LFD) has a significant effect on the bottleneck discharge rate: the higher the HOV LFD, the lower the bottleneck discharge rate. The effect of lane flow distribution and its relationship with bottleneck discharge rate on a weaving bottleneck formed by a lane drop and a busy off-ramp was studied. The results showed that the bottleneck discharge rate and lane flow distribution are linearly related and higher utilization of the median lane results in higher bottleneck discharge rate. / Dissertation/Thesis / Doctoral Dissertation Civil and Environmental Engineering 2014

Congestion is a world-wide problem in transportation. One major reason is random interruptions. The traffic network is inherently stochastic, and strong dependencies exist among traffic quantities, e.g., travel time, traffic speed, link volume. Information in stochastic networks can help with adaptive routing in terms of minimizing expected travel time or disutility. Routing in such networks is different from that in deterministic networks or when stochastic dependencies are not taken into account. This dissertation addresses the optimal routing problems, including the optimal a priori path problem and the optimal adaptive routing problem with different information scenarios, in stochastic and time-dependent networks with explicit consideration of the correlations between link travel time random variables. There are a number of studies in the literature addressing the optimal routing problems, but most of them ignore the correlations between link travel times. The consideration of the correlations makes the problem studied in this dissertation difficult, both conceptually and computationally. The optimal path finding problem in such networks is different from that in stochastic and time-dependent networks with no consideration of the correlations. This dissertation firstly provides an empirical study of the correlations between random link travel times and also verifies the importance of the consideration of the spatial and temporal correlations in estimating trip travel time and its reliability. It then shows that Bellman's principle of optimality or non-dominance is not valid due to the time-dependency and the correlations. A new property termed purity is introduced and an exact label-correcting algorithm is designed to solve the problem. With the fast advance of telecommunication technologies, real-time traffic information will soon become an integral part of travelers' route choice decision making. The study of optimal adaptive routing problems is thus timely and of great value. This dissertation studies the problems with a wide variety of information scenarios, including delayed global information, real-time local information, pre-trip global information, no online information, and trajectory information. It is shown that, for the first four partial information scenarios, Bellman's principle of optimality does not hold. A heuristic algorithm is developed and employed based on a set of necessary conditions for optimality. The same algorithm is showed to be exact for the perfect online information scenario. For optimal adaptive routing problem with trajectory information, this dissertation proves that, if the routing policy is defined in a similar way to other four information scenarios, i.e., the trajectory information is included in the state variable, Bellman's principle of optimality is valid. However, this definition results in a prohibitively large number of the states and the computation can hardly be carried out. The dissertation provides a recursive definition for the trajectory-adaptive routing policy, for which the information is not included in the state variable. In this way, the number of states is small, but Bellman's principle of optimality or non-dominance is invalid for a similar reason as in the optimal path problem. Again purity is introduced to the trajectory-adaptive routing policy and an exact algorithm is designed based on the concept of decreasing order of time.

Roadway crashes claim more than 30,000 lives each year in the United States, and they continue to affect the lives of people adversely. This problem becomes even more challenging when aging populations are considered due to their vulnerability and fragility to crashes. This is especially a major concern in Florida since the crash risk for the aging populations is increasing day by day proportional to the population growth of aging Floridians. This study investigates the spatial and temporal patterns of aging-involved crashes using Geographical Information Systems (GIS)-based methods with a case study on three urban counties in Florida. These counties are selected based on the high aging-involved crash rates, as identified by the Safe Mobility for Life Coalition of Florida. Among the methods studied, a network distance-based kernel density estimation method, namely SANET, is identified as a very effective tool since it provides an unbiased distribution of the crashes by calculating the actual distances between the crashes over the roadway network. GIS-based results are also supported with a binary logistic regression analysis in order to identify the significant factors affecting the aging-involved crashes. Results indicate that high risk locations for aging-involved crashes show different spatial and temporal patterns than those for other age groups. These pattern specific differences include the following: (a) Intersections have an adverse effect on the 65+ populations more than other adult age groups, (b) Aging-involved population crashes occur during the mid-day rather than the peak hours, which is not a similar pattern for other adult age groups, especially for the working populations, and (c) Weekdays have more aging-involved crashes than the weekends contrary to the other age group crashes. Investigating these distinct patterns thoroughly can lead to better aging-focused transportation plans and policies. / A Thesis submitted to the Department of Civil Engineering in partial fulfillment of the requirements for the degree of Master of Science. / Summer Semester 2015. / July 8, 2015. / Includes bibliographical references. / Eren Erman Ozguven, Professor Directing Thesis; John Sobanjo, Committee Member; Ren Moses, Committee Member.

Many claim that, with regard to transportation infrastructure, only partnerships between public and private entities, which draw on the strengths of both, can achieve the goals of enhancing operational efficiency, increasing service delivery, improving asset maintenance, and stretching scarce federal, state, and local tax dollars. While some completed public-private partnership (P3) agreements on existing toll roads in the United States have seen a measure of success, others have raised critical questions pertaining to the true costs and benefits associated with these agreements for all stakeholders. Of particular concern is an apparent reliance on monetary calculations alone to determine toll road lump sum value. This primary focus on monetary considerations appears to neglect a number of non-monetary variables associated with potential costs and benefits. Four distinct groups of variables to consider in the decision process are presented in the dissertation: Monetary, Monetizable, Quantitative, and Qualitative. The last two groups represent variables of a non-monetary nature, which can reflect the much larger stewardship role that government plays in our society. The objectives of this research are twofold: to formulate a conceptual framework for a decision support system (DSS); and to propose an approach, including a set of analytical methods, that assesses the costs, benefits and other impacts associated with alternative P3 strategies. The primary user of the conceptual framework is identified as the public sector decision maker who has been asked to make recommendations regarding different strategies of toll road operation. Two analytical methods are presented. The first uses cash flow diagrams to calculate the net present value (NPV) for each of three core P3 strategies. The second, weighs the relative importance of quantitative and qualitative (non-monetizable) variables. When used as part of a seven-step process, these two analytical methods help create a decision support system framework that provides stakeholders with a more complete analysis of the costs and benefits associated with the P3 toll road decision process.

Several recently published studies have demonstrated that employing planning strategies oriented on improving the internal characteristics of transit service, including frequency, coverage, intermodal integration, and seamless connectivity between all important trip attractors, positively influences ridership and productivity of multimodal bus and light rail transit systems. However, the research has not assessed overall economic outcomes of implementing these strategies, including social benefits and capital costs. Another emerging body of scholarship pointed to transit service contracting and consolidated regional governance as another possible strategy for improving transit feasibility. Again, not all economic aspects of these decisions have been evaluated thus far, and the available assessments of contracting and transit governance models do not consider long-term effects of specific organizational decisions. This study intends to fill these research gaps by investigating the influence of several internal and external transit performance factors on the amount of net benefits generated by 13 U.S. bus and light rail transit systems, observed annually during the 2001 - 2011 period. The evaluation starts with an estimation of net benefits (agency revenues plus non-direct social benefits minus operating and capital costs). Next, a panel regression model is employed to examine the statistical relationship between specific performance factors and the average net benefits generated by the case systems. The results of this study indicate that higher frequency, higher service density, higher ratio of contracted service and the presence of strong regional transit governance positively influence net benefits. The role of network decentralization (volume of service headed outside of the central business district) appears to be insignificant. These results bring additional evidence indicating the positive outcomes of certain internal transit planning strategies, which corresponds with the findings offered by previous research studies. / A Dissertation submitted to the Department of Urban and Regional Planning in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Fall Semester, 2014. / September 9, 2014. / benefit-cost analysis, light rail, public transportation, regional governance, transportation economics, transportation planning / Includes bibliographical references. / Jeffrey R. Brown, Professor Directing Dissertation; Keith Ihlanfeldt, University Representative; Andrew Aurand, Committee Member; Michael Duncan, Committee Member; Gregory L. Thompson, Committee Member.