working paper

The Determinants of Growth of Employment Subcenters

Publication Date

January 1, 1999

Associated Project

Abstract

This paper presents an empirical analysis of subcenter growth. We develop a series of hypotheses based on the theoretical concepts that have been proposed as explanations for the emergence and growth of subcenters. We then conduct tests of these hypotheses using 1970-80 data from the Los Angeles region. We find that subcenters containing fast-growing industries tended to grow rapidly, and so did those close to airports. There is weak evidence that large subcenters and those located near downtown Los Angeles grew more slowly in proportional terms, possibly indicating diseconomies of scale due to congestion.

working paper

Consumer E-Commerce, Virtual Accessibility and Sustainable Transport

Abstract

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.

policy brief

What Does the Prevalence of Telecommuting Mean for Urban Planning?

Abstract

Researchers at the University of California, Irvine, are looking into what may become the “new normal” in work and work-related travel and the consequences that could have on traffic conditions, efforts to address climate change, and the future of our urban areas, as well as our daily lives. They find, for instance, that current research is largely equivocal about the consequences of telecommuting on where individuals choose to live, their day-to-day travel, and urban/metropolitan development. Equally unclear is how increased telecommuting may impact efforts to create more sustainable and inclusive communities. In light of this uncertainty, they suggest planners and researchers need to pay more attention to the changing nature of urban commuting and how it can play an important role in shaping a more desirable future.

Suggested Citation
Alex Okashita, Harold Arzate and Jae Hong Kim (2024) What Does the Prevalence of Telecommuting Mean for Urban Planning?. Policy Brief. UC ITS. Available at: https://doi.org/10.7922/g2mc8xct.

working paper

A Comparative Assessment of Travel Characteristics for Neo-Traditional Developments

Publication Date

August 1, 1992

Associated Project

Working Paper

No. 142

Areas of Expertise

Abstract

The primary intent of this research is to explore the claim that transportation benefits can be derived from neo-traditional neighborhood design. Conventional transportation planning models are used as tools to evaluate the performance differences of two hypothetical street networks designed to replicate a neo-traditional and a conventional suburban community. Relative transportation benefits are measured in terms of vehicle-miles travelled (VMT), average trip lengths, and congestion on links and at intersections. This comparison provides an assessment of how well the two networks in question deal with trips generated by the activities which they serve. All aspects of the modelled communities are held constant except for the actual configuration of the networks. This type of evaluation can indicate, for example, whether the same level of activity (defined by the land uses within the community) creates greater congestion on one type of network, or if trip lengths on one network are generally longer. The ultimate goal is to determine if one network type, because of the nature of its design, can result in a more efficient transportation system.

Suggested Citation
Michael G. McNally and Sherry Ryan (1992) A Comparative Assessment of Travel Characteristics for Neo-Traditional Developments. Working Paper No. 142. Institute of Transportation Studies, UC Irvine: University of California Transportation Center. Available at: https://escholarship.org/uc/item/03n6593v.

policy brief

Advancing Community-Identified Strategies to Transform Roadways in California’s San Joaquin Valley

Abstract

Disparities in exposure to roadway hazards (e.g., pollution, noise) remain stubbornly persistent due to structural inequalities embedded in the built environment. Research has consistently documented racial/ethnic and socioeconomic disparities in traffic exposures nationwide, including heightened exposure to heavy-duty truck traffic, a significant source of noise and pollution. Such disparities also exist in the provision of sidewalks, bike lanes, and street trees, which can help mitigate roadway dust, noise, and pollution and can increase pedestrian safety, encourage walking and cycling, and provide health benefits. This publication describes how the research team evaluated opportunities and barriers to using a community steering committee process approach to advance environmental justice and transportation equity. Through interviews and case study analysis, the team examined the role community leaders played in the prioritization and implementation of three community-identified strategies that mitigate roadway hazards in three AB 617 communities in California’s San Joaquin Valley – Stockton, South Central Fresno, and Arvin/Lamont. These strategies include (1) vegetative barriers between roadways and sensitive land uses; (2) expanded sidewalk infrastructure; and (3) revised heavy duty truck route designations.

Suggested Citation
Douglas Houston (2025) Advancing Community-Identified Strategies to Transform Roadways in California’s San Joaquin Valley. Policy Brief. UC ITS. Available at: https://doi.org/10.7922/g29k48kd.

working paper

A Utility-Theory-Consistent System-of-Demand-Equations Approach to Household Travel Choice

Publication Date

September 1, 1998

Associated Project

Author(s)

Kara Kockelman

Abstract

Modeling personal travel behavior is complex, particularly when one tries to adhere closely to actual causal mechanisms while predicting human response to changes in the transport environment. There has long been a need for explicitly modeling the underlying determinant of travel – the demand for participation in out-of-home activities; and progress is being made in this area, primarily through discrete-choice models coupled with continuous-duration choices. However, these models tend to be restricted in size and conditional on a wide variety of other choices that could be modeled more endogenously.

This dissertation derives a system of demands for activity participation and other travel-related goods that is rigorously linked to theories of utility maximization. Two difficulties inherent in the modeling of travel – the discrete nature of many travel-related demands and the formal recognition of a time budget, not just a financial one – are dealt with explicitly. The dissertation then empirically evaluates several such demand systems, based on flexible specifications of indirect utility. The results provide estimates of activity generation and distribution and of economic parameters such as demand elasticities. Several hypotheses regarding travel behavior are tested, and estimates are made of welfare effects generated by changes in the travel environment.

The models presented here can be extended to encompass more disaggregate consumption bundles and stronger linkages between consumption of out-of-home activities and other goods. The flexibility and strong behavioral basis of the approach make it a promising new direction for travel demand modeling.

working paper

Simulating Travel Reliability

Abstract

We present a simulation model designed to determine the impact on congestion of policies for dealing with travel time uncertainty. The model combines a supply side model of congestion delay with a discrete choice econometric demand model that predicts scheduling choices for morning commute trips. The supply model describes congestion technology and exogenously specifies the probability, severity, and duration of non-recurrent events. From these, given traffic volumes, a distribution of travel times is generated, from which a mean, a standard deviation, and a probability of arriving late are calculated. The demand model uses these outputs from the supply model as independent variables and choices are forecast using sample enumeration and a synthetic sample of work start times and free flow travel times. The process is iterated until a stable congestion pattern is achieved. We report on the components of expected cost and the average travel delay for selected simulations.