Skip to main content
Open Access Publications from the University of California


The Center for Activity Systems Analysis (CASA) was established within the Institute of Transportation Studies at the University of California, Irvine to provide a focus for research in activity-based and agent-based models of travel and activity patterns and to foster interdisciplinary research in this and related areas. For over 25 years, CASA research associates have been on the leading edge of evolving research in activity systems analysis, establishing an international reputation in the study of complex travel behavior, activity-based approaches, agent-based models, microsimulation approaches, advanced data collection technologies including GIS and GPS, and empirical modeling.

Center for Activity Systems Analysis

There are 56 publications in this collection, published between 1995 and 2008.
Recent Work (56)

Consumer E-Commerce, Virtual Accessibility and Sustainable Transport

The growth of the Internet has rekindled interest in the relationship between communications and travel. New communication technologies have expanded the range, the type, and the number of transactions that can take place without travel. A number of promotions capture the new tradeoffs between communications and travel: initially, the Internet was referred to as “the information superhighway” and Microsoft ran an ad campaign dubbed “where do you want to go today?” The connection between travel and bytes has been summed up as “The Death of Distance” (Cairncross, 1997). A parallel evolution in telecommunication and transportation was envisioned more than 150 years ago with the inventions of the telegraph and telephone. The telephone was expected to “speed the movement of perishable goods,” “reduce the travels of salesmen,” and “let (itinerant) workers stay at home to be phoned for jobs” (Pool, 1983). Today, the Internet has fueled similar expectations, and many of them center on travelrelated issues. The Internet might relieve demand for new road capacity, slow down the rate of new vehicle ownership, and divert existing travel trips to less congested times. The Internet might help create more sustainable growth in transportation, by providing virtual accessibility. In this paper, we explore the transportation aspects of consumer electronic commerce (e-commerce). Shopping activities are currently automobileintensive in many countries, and increases in e-commerce could portend important changes in transportation patterns and activities.

How Households Use Different Types of Vehicles: A Structural Driver Allocation and Usage Model

The vehicle miles of travel for each vehicle in multi-vehicle households is modeled as a function of household characteristics, vehicle characteristics, and the matches of vehicle to driver in the satisfaction of travel desires. A structural equations model is developed in which principal driver characteristics, as well as vehicle miles of travel, are endogeneous. There are links between how each vehicle is used and who in the household is each vehicle's principal driver. Each vehicle's usage can then be expressed in reduced-form equations as a function of exogeneous household and vehicle type variables for forecasting purposes. The model is estimated on a 1993 sample of approximately 2000 multi-vehicle households in California.

Land Use Influences on Trip Chaining in Portland, Oregon

This paper examines the nature of land use based substitution effects on travel modes, identified by Greenwald, examining the direct impact of land uses inducing trip-making behaviors. These impacts are analyzed in the context of trip chaining, defined here as consolidating two or more non-home activities in a single departure from home. The findings suggest rather than strictly promoting one type of transportation over another, the regional impact of localized urban design practices is to consolidate trip making behavior closer to the home. As such, urban design “carrots” must be complemented with policy “sticks” in order to promote true exchanges of travel modes.

53 more worksshow all