Model-based Transportation Performance: A Comparative Framework and Literature Synthesis, Research Report 11-09

In an era of limited resources and a proliferation of data, there is increasing pressure to conduct careful evaluations of the economic, environmental, and equity effects of investments and policies that influence transportation and land-use systems. This report compares performance measures recommended to achieve desired goals and reviews the literature to determine the degree to which these measures have been implemented and what they indicate about the relative effectiveness of land-use, transit, and automobile pricing policies. Despite the variation in methods and performance measures implemented in the studies reviewed for this report, the synthesis of study results suggests the direction and relative magnitude of change resulting from different types of policies, as well as potential biases introduced by omitting the representation of the land-use and transportation interaction. Overall, the performance measures indicate that carefully designed transit, land-use, and automobile pricing policies may improve travel, economic, environmental, and equity conditions for communities. However, transit and peak-period automobile pricing policies can, in some situations, lead to negative performance outcomes across some or all measures, as illustrated in studies that explicitly represent the land-use and transportation interaction

Integrated Modeling Approach for the Transportation Disadvantaged

Transportation models have not been adequate in addressing severe long-term urban transportation problems that transportation disadvantaged groups overwhelmingly encounter, and the negative impacts of transportation on the disadvantaged have not been effectively considered in the modeling studies. Therefore this paper aims to develop a transportation modeling approach in order to understand the travel patterns of the transportation disadvantaged, and help in developing policies to solve the problems of the disadvantaged. Effectiveness of this approach is tested in a pilot study in Aydin, Turkey. After determining disadvantaged groups by a series of spatial and statistical analyses, the approach is integrated with a travel demand model. The model is run for both disadvantaged and nondisadvantaged populations to examine the differences between their travel behaviors. The findings of the pilot study reveal that almost two thirds of the population is disadvantaged, and this modeling approach could be particularly useful in disadvantage-sensitive planning studies to deploy relevant land use and transportation policies for disadvantaged groups

Assessment of the Employment Accessibility Benefits of Shared Autonomous Mobility Services

The goal of this study is to assess and quantify the potential employment accessibility benefits of Shared Autonomous Mobility Service (SAMS) commute modes across a large diverse metropolitan region considering heterogeneity in the working population. To meet this goal, this study employs a welfare-based (i.e. logsum-based) measure of accessibility, obtained via estimating a hierarchical work destination-commute mode choice model. The employment accessibility logsum measure incorporates the spatial distribution of worker residences and employment opportunities, the attributes of the available commute modes, and the characteristics of individual workers. This research further captures heterogeneity of workers using latent class analysis (LCA). The LCA model inputs include the socio-demographic characteristics of workers to subsequently account for different worker clusters valuing different types of employment opportunities differently. The accessibility analysis results indicate: (i) the accessibility benefit differences across latent classes are modest but young workers and low-income workers do see higher benefits than high- and middle-income workers; (ii) there are substantial spatial differences in accessibility benefits with workers living in lower density areas benefiting more than workers living in high-density areas; (iii) nearly all the accessibility benefits come from the SAMS-only mode as opposed to the SAMS+Transit mode; and (iv) the SAMS cost per mile assumption significantly impacts the magnitude of the overall employment accessibility benefits

Measuring Incremental SB743 Progress: Accounting for Project Contributions Towards Reducing VMT Under California\u27s Senate Bill 743

On September 27, 2013, California’s governor signed Senate Bill (SB) 743 into law, in part mandating the transition from a level-of-service-based (LOS) measure of transportation environmental impacts to a vehicle-miles-traveled-based (VMT) one in compliance with the California Environmental Quality Act (CEQA). Several California jurisdictions, including San Jose, Pasadena, and San Francisco, have moved quickly to comply with SB 743, so it is no surprise that several of these early-adopter cities have been working hard to develop powerful VMT estimation methods and tools using the most recent research available. This perspective uses the experiences of an early-adopter city, San Jose, to identify and illustrate the challenges faced by California planners trying to meet the legal requirements of SB 743 and the practical needs of their communities in developing the VMT calculation methods

Investigation to enhance sustainable improvements in high speed rail transport

Transport systems are essential for the life of modern societies and economies. A sustainable transport system can shape a sustainable development pattern and socio-economic attributes of urban centres and regions. The use of private cars and trucks is increasing in most countries, creating more congestion, accidents, pollution and energy consumption. Many governments desire to achieve growth in public transport to overcome these adverse trends. A massive shift toward an environmentally sound type of transport is crucial and railways are deemed to be one of the most sustainable modes. All over the world the railway industry is involved in a renewal to reform and up-date rail, prompted largely by environmental concerns. The trend is to develop speed-competitive systems to expand transportation capacity. The focus of the current research, which is at its commencing stages, is to investigate the opportunities to apply an alternative approach to railway operations to overcome the difficulty of high speed transport in servicing larger amounts of demand, while achieving minimum point to point travel time, in a viable and integrated environment for both passenger and freight services. The expected outcome of the research project is to present a framework that may be used to identify and evaluate the most cost-effective transport solution to service not only major cities, but also regional centres along an interregional rail corridor, thus providing greater benefits on local economies and to build a spine for future development

A Multi-modal Trip Distribution Model

This paper presents a multimodal trip distribution function estimated and validated for the metropolitan Washington region. In addition, a methodology for measuring accessibility, which is used as a measure of effectiveness for networks, using the impedance curves in the distribution model is described. This methodology is applied at the strategic planning level to alternative HOV alignments to select alignments for further study and Right-of-Way preservation. .

Implementation of the Delta/Start Model.

This working paper outlines the steps undertaken to develop a dynamic land use transport model. The model is based around an existing transport modelling suite, called START, which has been applied to many urban areas in the UK and abroad. However, its integration with an explicit land use model (called DELTA) was new, and this paper describes the first implementation of the combined dynamic land use transport model for the study area of Fife and Lothian region. The model was used in a PhD thesis and an EPSRC ‘Sustainable Cities’ research project at the Institute for Transport Studies. The paper discusses the processes involved in the full implementation of this model, involving both software development, modification to existing software, and implementation. However, it focuses in particular upon the data requirements and calibration of the various submodels in DELTA. In general the model dataset has been generated using existing study area data from past START applications, plus data from the 1991 Census of population and employment. Not all the disaggregations of data required by the model were available from published, or on-line, sources, and so several disaggregations were undertaken. A feature of the model is that the calibration is undertaken for each submodel individually. In general, the model made use of past research into the relationships that it represents, combined with the judgement of the model developers where no other data was available. The implementation of the location model is discussed in detail, including the use of environmental variables in location choice. This fulfils the main aim of this paper; to provide the technical background for the research projects that make use of this model implementation

Accessibility Futures.

This study uses accessibility as a performance measure to evaluate a matrix of future land use and network scenarios for planning purposes. Previous research has established the coevolution of transportation and land use, demonstrated the dependence of accessibility on both, and made the case for the use of accessibility measures as a planning tool. This study builds off of these findings by demonstrating the use of accessibility-based performance measures on the Twin Cities Metropolitan Area. This choice of performance measure also allows for transit and highway networks to be compared side-by-side. A zone to zone travel time matrix was computed using SUE assignment with travel time feedback to trip distribution. A database of schedules was used on the transit networks to assign transit routes. This travel time data was joined with the land use data from each scenario to obtain the employment, population, and labor accessibility from each TAZ within specified time ranges. Tables of person- weighed accessibility were computed for 20 minutes with zone population as the weight for employment accessibility and zone employment as the weight for population and labor accessibility. The person-weighted accessibility results were then used to evaluate the planning scenarios. The results show that centralized population and employment produce the highest accessibility across all networks.Accessibility, Forecasting, Travel Demand, Scenarios, Trends, Transportation, Land Use.