conference paper
working paper
Long records of activities and travel for individuals, essential for understanding the dynamic changes in traveler behavior, do not exist due to the difficulty of collecting such data. To address this need, an on-line activity survey was designed that is tightly intertwined with real-time position data streaming over wireless data links from in-vehicle GPS data collection devices. While the technology to construct such a survey has existed for some time, the author has been unable to find other published examples of such as survey system. Some preliminary observations of the system based on a small, informal pilot survey are reported.
working paper
Methanol offers much promise as an alternative fuel whose combustion produces no sulfates and fewer nitrogen oxides and particulates than diesel. As another advantage, large quantities could be manufactured from domestic coal supplies. Believing that an extensive methanol program might well begin with public transit, we estimate the costs and benefits of converting the bus fleets of California’s South Coast Air Basin to methanol. Benefits are based on the reduced mortality attributable to lower sulfates and particulates; costs encompass both bus conversion and replacement. Comparing these benefits with costs over a wide range of methanol prices, we find that conversion to methanol merits further consideration as an anti-pollution strategy. We propose to extend the analysis to additional potential benefits and costs, and to other locales and types of vehicles.
published journal article
About 7 percent of California households do not own motor vehicles. Unfortunately, families without cars, trucks, vans, SUVs, or motorbikes are rarely the focus of transportation research and policies, which typically center more on predicting and managing motor vehicle traffic. Widespread automobile ownership has shaped our society by enhancing mobility for most, but these benefits have come at the cost of frequent collisions, heavy traffic congestion, substantial carbon emissions, and widespread noise pollution. In 2015, California Gov. Jerry Brown signed an executive order requiring the state to reduce greenhouse gas emissions to 40 percent below 1990 levels by 2030, accelerating goals previously set by Assembly Bill 32 and Senate Bill 375. While these laws and executive orders have turned reducing vehicle-miles traveled into a prominent policy goal, the path away from an auto-dependent society is far from clear. Accordingly, researchers and policymakers can learn a great deal from the households who live without motor vehicles. To do this, we must first distinguish between â??voluntarily carless households,â?? who have chosen to not own motor vehicles, and â??involuntarily carless households,â?? who are carless by necessity.
conference paper |
Jan 2018
published journal article |
Dec 2017
published journal article |
Dec 2020
policy brief |
May 2020
research report |
May 2018
published journal article
working paper
The product of this research is a dynamic simultaneous equations model of car ownership and modal travel distances as a function of income. The data are from the Dutch National Mobility Panel (1984-1987); and four modes are encompassed: car driver, car passenger, train, and bus-tram-subway. A novel feature of the simultaneous equation system is the consistent treatment of the measurement scales of the variables: ordered probit functions for income and car ownership and tobit functions for distances. The dynamics are expressed in terms of pooled panel survey measurements of the variables at two points in time one year apart. This allows the identification of lagged responses and serial correlations over a one-year time-horizon. Results indicate that increased car ownership and car kilometers at time T2 is influenced by heavy usage of other modes at time T1. This indicates there are significant noninstantaneous adjustments of car ownership and usage that represent modal substitutions.
working paper |
Jun 1989
working paper |
Nov 1991
working paper |
Jun 1991
working paper |
Nov 1988
working paper |
Sep 1991
published journal article
Phd Dissertation
Forecasting the demand for alternative-fuel vehicles (AFVs) is quite important for manufacturers, fuel suppliers and environmental planners. AFVs have attributes such as reduced range and limited refueling options that are very different from existing vehicles. Therefore stated preference (SP) data is necessary for demand models. Previous work by Brownstone, Bunch, and Train (1998) shows that there are serious biases in these stated preference data. Another source of households’ vehicle preference, is households’ actual observed transaction behavior (Revealed preference (RP) data). I develop a dynamic stated and revealed preference vehicle transaction model which uses the RP data to control for the biases of using pure SP data in order to better forecast households’ demand for AFVs for California. I implement a “scale factor” to specify the relationship of the different variances of the RP and SP data. Moreover, I examine the nested structure over different fuel-type vehicle choices and estimate both the multinomial logit (MNL) and nested logit (NL) models. In addition, I conduct forecast using the pure SP and joint SP-RP MNL models under the scenario consisting of new vehicle technologies for year 1998. Compared to the new vehicle sales statistics, it is obvious that the joint SP-RP model provides more reasonable forecasts. I also examine the different substitution patterns implied by the pure SP MNL and NL models when new vehicle choices are introduced. The NL model predicts more realistic substitution pattern. I also add the used vehicle choices to the forecast scenario to make the forecast more realistic because the used vehicle market is taken into consideration. Large panel data sets have been collected by the California Alternative-Fuel Vehicle Demand Forecast Project since May 1993. These data contain extensive information on households’ stated and revealed preference vehicle transactions, vehicle utilization and households’ socioeconomic characteristics. This study serves as an example of how to forecast new products or technologies that mark considerable departures from existing products or technologies.
research report
Illustrates the application of the Irvine Performance Evaluation Method (IPEM) to triennial reviews of transit performance conducted by the Urban Mass Transportation Administration under provisions of the Surface Transportation Assistance Act of 1982
conference paper
