Current Faculty Research Grants
R02-5 |
Patricia Mokhtarian Fully understanding the potential transportation impacts of new (internet) and old (going to the store, catalog) shopping alternatives requires investigating the adoption of the various alternatives. By now, numerous studies have analyzed (intended or actual) purchase or pre-purchase (search) behavior, but we are not aware of any empirical studies considering the combined choices of pre-purchase and purchase modes. Yet it is important to understand those choices not as separate and independent, but rather as interrelated. This study continues the substantive analysis of data collected from an original survey of shopping attitudes and behavior, in this phase investigating the combined choices of pre-purchase and purchase modes (primarily store and internet, but also catalog and other pre-purchase modes). We propose to (1) cluster cases based on a variety of possible pre-purchase/purchase mode patterns; (2) conduct descriptive analyses of the resulting clusters, using the large variety of personality, attitudinal, situational, and sociodemographic variables available to us; and (3) develop multivariate probit and/or multidimensional nested logit models of pre-purchase and purchase mode choice combinations. The findings will have important implications for transportation planning as well as for the retail industry. |
R02-4 |
Susan Handy As a means of transportation and as a form of physical activity, bicycling generates benefits to the bicyclist as well as to the community as a whole. Bicycling now accounts for less than 1 percent of all trips for all purposes in the U.S., but evidence from other western countries suggests that under the right conditions, bicycling levels can be significantly higher. The experience of Davis, California suggests that it is possible to create conditions conducive to higher levels of bicycling in the U.S. However, the extent to which bicycling policy has contributed to bicycling levels in Davis has not been rigorously assessed. This project aims to fill that gap through cross-sectional and quasi-longitudinal studies of bicycling behavior in Davis and comparison communities designed to determine the influence of bicycle infrastructure and mixed-use land use patterns relative to individual preferences, community culture, and other factors. This project focuses on the analysis of data collected using an on-line survey in Davis and five comparison cities in early fall 2006 and the development of a survey of students at Davis High and selected comparison schools. This project completes Phase 1 and begins Phase 2 of the Davis Bicycle Studies. |
R02-3 |
Yueyue Fan We propose to develop methods for sequentially building networks of HOT lanes, with objective of achieving system efficiency, social equitability, and financial sustainability. A mathematical model that integrates multistage decision processes, optimization techniques, and user behavior model will be developed to identify the optimal sequence of converting existing and under-construction HOV facilities to HOT lanes and the associated pricing strategies. Various system performance measures will be considered including total toll revenue, total vehicle delay, and total costs for the users. The requirement on equitability, measured by the gap between the rich and the poor in terms of benefits from the implementation of HOT lanes, is explicitly included as model constraints to ensure a solution that is more likely to be accepted by all income groups. The multistage framework allows optimal usage of toll revenue gained from implemented HOT segments for financing future HOT projects, thus imposes less financial burden on public agencies and future generations. These unique modeling treatments are proposed to enhance the overall sustainability of the transportation network in question. Case studies based on selected corridors in San Francisco Bay Area will be carried out for numerical testing, sensitivity analysis of model parameters, and policy implications. |
R02-2 |
Mark Delucchi We propose that it is possible to build communities that accommodate strong preferences for auto-mobility and single-family homes, yet at the same time are much safer and cleaner, more pleasant, and more socially integrated than conventional suburbs. We accomplish this with a dual transportation infrastructure: the complete separation of fast, heavy vehicles (FHVs) from low-speed, low-speed, lightweight modes (LLMs; less than 25 mph top speed and 500 kg curb weight) on a city-wide scale. In a draft report (Delucchi et al, 2002) we delineate our dual-road-system plan and discuss and analyze some of its impacts on transportation problems. The potential environmental, social, and community benefits of the plan are clear. However, for these benefits to be realized, people must choose to live in such planned communities and to buy and use LLMs. Because there are no communities like the one we propose, one must use simulations to begin to understand how people might react to our plan. We seek STC funding to design and administer “pilot” household interviews, focus groups, and other group interviews to investigate: i) effective ways to represent or simulate life and travel in our plan; ii) how people react to various aspects of the plan; iii) the implications of our initial findings for developing the plan to maximize its appeal to households, and iv) the practical problem of how to start to build such towns as we propose. |
R02-1 |
Alison Berry Roads and road networks have environmental impacts that vary in type and degree based on the physical properties of the roadway, the activities associated with the road, and the sensitivity of the local environment. The local environment affected by the road surface and traffic has been termed the “road effect zone”. Although there is a rapidly growing literature on specific environmental impacts within this zone (storm-water runoff effects, biological invasions, noise, wildlife barriers), there have been few tests of the extent of the road effect zone, how various impacts are interrelated, and how these impacts could be minimized through pavement and roadside management activities. The objectives of the proposal are: 1) To develop a long-term integrated experimental site at the newly-established UC Davis Advanced Transportation Infrastructure Research Center, and 2) To establish a modeling framework for future research on the road effect zone, with special emphasis on defining parameters of relevance for California road systems, but with methodologically broader applicability. |
R01-5 |
Patricia Mokhtarian Why do some individuals want to travel more, and others less? Just asking this question is novel, as most transportation researchers consider travel to be strictly a cost necessary to participate in daily life activities. That premise is challenged here in a “first principles” examination of travel behavior. Four key travel-related constructs are defined: objective mobility, subjective mobility, travel liking, and relative desired mobility. A 1998 survey measured these variables for travel segmented by length, purpose, and mode, as well as attitudes, personality, lifestyle, and socio-demographics, for more than 1,300 workers in the San Francisco Bay Area. Prior analysis of this dataset has involved only single-equation models, and has exposed considerable endogeneity among the four key constructs. Here, structural equation modeling will be used to sort out the inter-relationships among these endogenous variables, as well as other relationships present in the dataset. The findings will have important implications for our understanding and prediction of travel behavior. |
R01-4 |
Michael Zhang We hypothesize that using a realistic dynamic flow model may significantly alter the policy implications and welfare effects of a time-varying toll derived from the basic bottleneck model. In the proposed research, we plan to test our hypothesis by exploring dynamic congestion pricing on a wide variety of simple yet general networks with a more realistic traffic flow model. To achieve this objective, we will formulate, solve and analyze the dynamic congestion pricing problem via traffic equilibrium analysis and network optimization, and discuss the policy implications of our research findings. |
R01-3 |
Ken Kurani Rising gasoline prices, greenhouse gas emissions, and war in oil-producing regions motivate this research on whether drivers would reduce their petroleum consumption if they received feedback on their energy use. This proposed study examines effects of energy-use feedback on household drivers of conventional and hybrid light-duty passenger vehicles. Drivers will be interviewed and commercially available devices will be installed in some drivers’ vehicles. This qualitative study is expected to produce insights into specific types of driver response to feedback mechanisms and to produce the requisite knowledge to design and deploy a larger scale study to produce estimates of effects that can be generalized. |
R01-2 |
Susan Handy Bicycling now accounts for less than 1 percent of all trips for all purposes in the United States, but evidence from other western countries suggests that under the right conditions, bicycling levels can be significantly higher. The experience of Davis, California suggests that it is possible to create conditions conducive to higher levels of bicycling in the U.S. However, the extent to which bicycling policy has contributed to bicycling levels in Davis has not been rigorously assessed. This project aims to fill that gap through a quasi-experimental study of bicycling behavior in Davis and comparison communities. The study will be designed to determine the influence of bicycle infrastructure and mixed-use land use patterns relative to individual preferences, community culture, and other factors. |
R01-1 |
Alison Berry Transportation planners increasingly need effective metrics for determining the effect of transportation systems on biological systems. Developing the metric and measuring the impact is the first step toward mitigation. Professor Alison Berry proposes to develop effective mesh size, effective mesh density and landscape division as metrics of habitat fragmentation for use in transportation planning. These innovative and biologically meaningful measures of landscape fragmentation will be applied to the mapped ranges of 10 key animal species. Final products from the proposed effort will serve as a model and metric for transportation planners throughout the world. |