Recent itsirvine_wps items

Charging Infrastructure Decisions by Heavy-duty Vehicle Fleet Operators: An Exploratory Analysis

Sat, 25 Jan 2025 00:00:00 +0000

Insufficient charging/fueling infrastructure poses a major challenge to achieving U.S. policy goals for transitioning the heavy-duty vehicle (HDV) sector to zero-emission vehicles. Addressing the infrastructure needs of HDV fleet operators, who are key demand-side stakeholders, is crucial for developing effective solutions and strategies. This study investigates these needs through a fleet survey of California’s drayage sector, focusing on battery electric trucks. Key aspects examined include preferences for charging locations, access types, charging duration, time-of-day for charging, and innovative solutions like Truck-as-a-Service. Analyzing responses from 53 companies with varying fleet sizes, annual revenues, and operational characteristics, the study employed a comprehensive exploratory approach, utilizing descriptive analysis, thematic analysis, and hypothesis testing. Findings reveal that while most fleets preferred on-site...

A Choice Experiment Survey of Drayage Fleet Operator Preferences for Zero-Emission Trucks

Sat, 25 Jan 2025 00:00:00 +0000

Many U.S. states are supporting the transition of the heavy-duty vehicle (HDV) sector to zero-emission vehicles (ZEVs), with California leading the way through its policy and regulatory initiatives. Within various HDV fleet segments, California’s drayage fleets face stringent targets, requiring all vehicles newly registered in the Truck Regulation Upload, Compliance, and Reporting System to be ZEVs starting January 2024, and all drayage trucks in operation to be zero-emission by 2035. Understanding fleet operator behavior and perspectives is crucial for achieving these goals; however, it remains a critical knowledge gap. This study investigates the preferences and influencing factors for ZEVs among drayage fleet operators in California. We conducted a stated preference choice experiment survey, developed based on previous qualitative studies and literature reviews. With participation from 71 fleets of various sizes and alternative fuel...

A Comparison of Time-use for Telecommuters, Potential Telecommuters, and Commuters during the COVID-19 Pandemic

Wed, 10 Jul 2024 00:00:00 +0000

Throughout the ongoing COVID-19 pandemic, changes in daily activity-travel routines and time-use behavior, including the widespread adoption of telecommuting, have been manifold. This study considers how telecommuters have responded to the changes in activity-travel scheduling and time allocation. In particular, we consider how workers utilized time during the pandemic by comparing workers who telecommuted with workers who continued to commute. Commuters were segmented into those who worked in telecommutable jobs (potential telecommuters) and those who did not (commuters). Our empirical analysis suggested that telecommuters exhibited distinct activity participation and time use patterns from the commuter groups. It also supported the basic hypothesis that telecommuters were more engaged with in-home versus out-of-home activity compared to potential telecommuters and commuters. In terms of activity time-use, telecommuters spent less time on work activity but more time on caring...

Transportation Access, Urban Problems, and Intrametropolitan Population and Employment Changes

Tue, 1 Nov 2022 00:00:00 +0000

This study examines the competing roles of transportation access and urban problems in the continuing suburbanization of American metropolitan areas. In particular, the paper asks whether suburbanization is primarily an adjustment to existing transportation networks, as predicted by the monocentric urban model, or whether decentralization is the result of persons and firms fleeing a host of central city problems, as is more consistent with a Tiebout model. This question is empirically tested by examining the determinants of population and employment changes for 365 northern New Jersey municipalities in the 1980s. The findings suggest that both transportation access and intra-metropolitan differences in local characteristics are important determinants of municipal population and employment changes. Furthermore, transportation access and local characteristics have roughly equal policy importance. This suggests that policies aimed at controlling land use patterns should be cognizant...

Economies of Scale and Self-Financing Rules with Noncompetitive Factor Markets

Tue, 1 Nov 2022 00:00:00 +0000

When a firm or public authority prices output at marginal cost, its profits are related to the degree of local economies of scale in its cost function. As is well known, this result extends to the case where some congestion-prone inputs are supplied by users. I show that contrary to common belief, the result holds even when scale economies are affected by a rising factor supply curve. In that case, constant returns to scale in production produces diseconomies of scale in the cost function, making marginal-cost pricing profitable. Examples are provided for a monopsonist both with and without price discrimination. In the latter case, second-best pricing is also considered: profits then are not governed in the usual way either by returns to scale in production or by scale economies in the cost function, but some useful bounds are provided.

Predicting the Market Penetration of Electric and Clean-Fuel Vehicles

Tue, 1 Nov 2022 00:00:00 +0000

Air quality in Southern California and elsewhere could be substantially improved if some gasoline powered personal vehicles were replaced by vehicles powered by electricity or alternative fuels, such as methanol, ethanol, propane, or compressed natural gas. Quantitative market research information about how consumers are likely to respond to alternative-fuel vehicles is critical to the development of policies aimed at encouraging such technological change.

In 1991, a three-phase stated preference (SP) survey was implemented in the South Coast Air Basin of California to predict the effect on personal vehicle purchases of attributes that potentially differentiate clean-fuel vehicles from conventional gasoline (or diesel) vehicles. These attributes included: limited availability of refueling stations, limited range between refueling or recharging, vehicle prices, fuel operating costs, emissions levels, multiple-fuel capability, and performance. Respondents were asked...

The Demand for Transportation: Models and Applications

Tue, 1 Nov 2022 00:00:00 +0000

This chapter describes how transportation demand is analyzed and what has been learned from doing so. We first present a selection of the most important transportation demand models, with an emphasis on disaggregate models because they have generally been the most successful in capturing essential features of travel behavior. We then show how the models have enriched our substantive knowledge of the demand for transportation, and discuss how they have been used to address important transportation policy issues.

Transportation, Stress and Community Psychology

Tue, 1 Nov 2022 00:00:00 +0000

Conditions of transportation were investigated as sources of psychological stress as they affect the physiology, task performance, and mood stress of commuters. Participants in the study were 100 employees of industrial firms. Traffic congestion was construed as a behavioral constraint in terms of the concept of impedance which is defined by the parameters of distance and time. It was expected that the effects of impedance would be mediated by personality factors, such as locus of control. Multivariate tests of the internal validity of the impedance factor were significant. However, significant main effects for impedance were only obtained for mood and residential adaptation. The predicted interactions of impedance with locus of control were obtained across task performance indices. In multiple regression analyses, the distance and speed of the commute to work were found to account for significant proportions of variation in blood pressure, while several indices of personal control...

Joint Modelling of Attitudes and Behaviour in Project Evaluation: Case Study of Single-Occupant Vehicle Toll Use of Carpool Lanes in San Diego, California

Tue, 1 Nov 2022 00:00:00 +0000

Knowing what people think about the usefulness, fairness, and success of new transport initiatives is vital information for planners and project evaluators. Methods for studying the complex relationships between attitudes and choice behaviour need to be included in evaluation processes.

The attitudes of an individual faced with a new transport option will depend in part on whether the individual can take advantage of the new option, whether he or she actually chooses to take advantage, and the perceived benefits of the option, to the individual and to the community. Transport planners use choice models to understand factors affecting demand, but modelling of attitudes has not received similar attention. In this paper we demonstrate how a joint model of attitudes and behaviour can be used in comprehensive project evaluation. The approach involves analysing attitude survey data using a structural equations model designed for use with discrete choice and ordinal-scale...

Demand for Clean-Fuel Personal Vehicles in California: A Discrete-Choice Stated Preference Survey

Tue, 1 Nov 2022 00:00:00 +0000

A study was conducted to determine how demand for clean-fuel vehicles and their fuels is likely to vary as a function of attributes that distinguish these vehicles from conventional gasoline vehicles. For the purposes of the study, clean-fuel vehicles are defined to encompass both electric vehicles, and unspecified (methanol, ethanol, compressed natural gas or propane) liquid and gaseous fuel vehicles, in both de or multiple-fuel versions. The attributes include vehicle purchase price, fuel operating cost, vehicle range between refueling, availability of fuel, dedicated versus multiple-fuel capability, and the level of reduction in emissions (compared to current vehicles). In a mail-back stated preference survey, approximately 700 respondents in the California South Coast Air Basin gave their choices among sets of hypothetical future vehicles, as well as their choices between alternative fuel versus gasoline for hypothetical multiple-fuel vehicles. Estimates of attribute importance...

Forecasting Electric Vehicle Ownership and Use in the California South Coast Air Basin

Tue, 1 Nov 2022 00:00:00 +0000

This research deals with demand for automobiles and light-duty and medium-duty trucks. Planners concerned with energy consumption, air quality and the provision of transportation facilities must have dependable forecasts of vehicle ownership and use from both the residential (personal-use vehicle) sectors and the fleet (commercial and governmental) sectors. As long as vehicles evolved slowly, it was possible to base such forecasts on extrapolations of observed demand. However, in an era of increasing environmental awareness, mandated in part by the Clean Air Act Amendments (US EPA, 1990), government agencies are now concerned with promoting clean-fuel vehicles; vehicle manufacturers are faced with designing and marketing clean-fuel vehicles; and suppliers of fuels other than gasoline must plan infrastructure and pricing policies.

Clean Air Forever? A Longitudinal Analysis of Opinions about Air Pollution and Electric Vehicles

Tue, 1 Nov 2022 00:00:00 +0000

Many current initiatives to develop the electric vehicle depend upon public perception that electric vehicles (EVs) are good for the environment. This study investigates how people acquire information about the environment and EVs, and whether their opinions about environmental efficacy change over time and experience levels. These issues are explored across two data sets. The first data set is a panel survey of California households (n=1718) and environmental opinions are tracked over two waves of survey. A decline in the environmental ethos is associated with several factors, including interpersonal communications and exposure to more specialized media. A sample of households from the panel study were subsequently chosen, among others, to participate in a two-week long trial of EVs (n=69). Opinions about environmental efficacy are studied as users gain first hand knowledge of an EV. Opinions about the environmental efficacy of the EV show improvement, but trial users become...

The Effects of Consumer Beliefs and Environmental Concerns on the Market Potential for Alternative-Fuel Vehicles

Tue, 1 Nov 2022 00:00:00 +0000

The objective of the present study is to identify relationships that exist among: (i) intentions to purchase alternative-fuel vehicles prior to their large-scale introduction, (ii) attitudes toward the environment, (iii) perceived importance of convenience and economy of ownership and operation, and (iv) consumer uncertainties. The intent is to unveil what factors, if any, may impede the promotion of alternative fuels, and, in turn, offer some guidelines for successful marketing of alternative-fuel vehicles. The study results can also aid in future stated preference demand estimation surveys by identifying factors that are likely to play important roles in the purchase of alternative vehicles.

Rational Response to Irrational Attitudes: The Level of the Gasoline Tax in the United States

Tue, 1 Nov 2022 00:00:00 +0000

Retailers often price items at $9.99 rather than $10.00. They may do so to fool consumers into viewing the price as closer to $9.00 than to $10.00, or to signal consumers that the product is on sale (e.g., Stiving and Winer, 1997). Similarly, workers highly desire a six-figure income-a salary of $100,000 sounds much more impressive than a salary of $99,999.

This paper explores related behavior by government. Suppose legislators attempt to reduce the salience of increases in the gasoline tax by avoiding moving gasoline taxes into double digits, and suppose that once taxes are moved beyond the double-digit threshold, legislators might as well raise them a little more than just the threshold increment to compensate for the increased visibility they have incurred. Two patterns might result: relatively few states imposing a tax of exactly 10 cents, and a more general avoidance of double-digit taxes. The data confirm this pattern.

Such attention to nominal...

Hypercongestion

Tue, 1 Nov 2022 00:00:00 +0000

The standard economic model for analyzing traffic congestion, due to A.A. Walters, incorporates a relationship between speed and traffic flow. Empirical measurements indicate a region, known as hypercongestion, in which speed increases with flow. We argue that this relationship is unsuitable as a supply curve for equilibrium analysis because hypercongestion occurs as a response to transient demand fluctuations. We then present tractable models for handling such fluctuations, both for a uniform expressway and for a dense street network such as in a central business district (CBD). For the CBD model, we consider both exogenous and endogenous time patterns for demand, and we make use of an empirical speed-density relationship for Dallas, Texas to characterize both congested and hypercongested conditions.

Private Toll Roads: Learning From the Nineteenth Century

Tue, 1 Nov 2022 00:00:00 +0000

Modern experimentation with privately built and operated toll roads has an enormous precedent in 19th century America. Over 2,000 private companies operated toll roads, financed mainly by voluntary stock subscription. The paper describes the old movement and makes a point by-point comparison between the old toll roads and the modern toll roads. Proponents of modern toll road can benefit from a knowledge of their predecessors' experience with regulation, concessions based on equity, and the role of local communities in deciding the fate of projects.

Modelling the Choice of Clean Fuels and Clean Fuel Vehicles

Tue, 1 Nov 2022 00:00:00 +0000

Reducing vehicle emissions levels is particularly important in the South Coast Air Basin of California, which includes the Los Angeles Metropolitan Area and the adjacent and interdependent Orange County, Riverside, and San Bernardino Metropolitan Areas. The climate and topography create ideal conditions for the area's infamous smog; and cars, trucks and buses contribute 88 percent of carbon monoxide emissions and about 50 percent of the ozone components: oxides of nitrogen and reactive organic gases. It is apparent that air quality can be greatly improved if gasoline-powered personal vehicles can be replaced in substantial numbers by vehicles powered by electricity or alternative fuels, such as methanol, ethanol, propane, or compressed natural gas (CNG) (see Sperling, 1988 and National Research Council, 1990, for discussions of the environmental factors associated with specific alternative fuels). While none of these alternative fuels has zero-level emissions (even electricity,...

Benefits, Acceptance, and Marketability of Value-Priced Services: California's Route 91 Express Lanes

Tue, 1 Nov 2022 00:00:00 +0000

Transportation professionals have always been interested in how travelers respond to different transportation options. A new application of congestion pricing offers the opportunity to extend such research to situations where travelers face a priced alternative. Travelers along State Route 91 (SR 91) in Southern California can now pay a time-varying fee in order to travel on a set of essentially congestion-free "Express Lanes" located in the median of a very congested preexisting freeway. For this study, we conduct a mail survey of such travelers to learn how they decide to use the free lanes or the toll lanes. We use the data to estimate route choice models and models that incorporate various types of real-time information about accidents, traffic conditions, and price levels into the route choice decision. This study provides new information about the acceptance of congestion pricing, the use of real-time information in making dynamic travel decisions, and individual travelers'...

Simulating Travel Reliability

Tue, 1 Nov 2022 00:00:00 +0000

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.

Projecting Use of Electric Vehicles from Household Vehicle Trials: Trial and Error?

Tue, 1 Nov 2022 00:00:00 +0000

In 1995-96, the authors participated in an eight-month long trial of prototype EVs, with the proviso that we could use some of the results for academic research. We were particularly interested in comparing data collected from trials with matched data collected from a panel survey. Our objective was to better understand vehicle trials as a source of information for transportation planning and market research, beyond the usual consumer preference information gathered for vehicle design purposes. The methodological issues were of particular concern, for as we discuss in the next section, trials provide useful data at one level, but they can also introduce new sources of bias and uncertainty to data collection and interpretation. We also investigated how perceptions towards EVs would change with the "hands-on" experience of a trial.

In this paper we report findings from this trial, with a particular emphasis upon the methodological issues. We intentionally do not discuss...

Using the Revenues From Congestion Pricing

Tue, 1 Nov 2022 00:00:00 +0000

Congestion pricing has many goals and benefits, but one thing is clear: its success depends on wise use of the revenues. The economic theory behind the concept relies on these revenues to help compensate for the payments required of highway users. Practical and ethical considerations similarly dictate that those who would otherwise be harmed by the fees receive tangible benefits from the revenues.

This paper investigates the possibilities for designing a package of congestion prices and revenue uses that can attract wide support. The suggested approach returns two-thirds of the revenues to travelers through travel allowances and tax reductions, and uses the rest to improve transportation throughout the area and provide targeted services to affected business centers. By replacing regressive sales and fuel taxes, this approach offsets the tendency of the prices alone to have a regressive distributional impact. By lowering taxes, funding new highways, improving transit,...

Measuring Traffic Congestion

Tue, 1 Nov 2022 00:00:00 +0000

We develop a traffic congestion index using data for California highways from 1976 through 1994. The technique yields a congestion measure which has several advantages. The index developed here can be applied to counties, urbanized areas, highway segments, or other portions of geographic areas or highway networks. The index allows cross-sectional and time series comparisons which have only rarely been possible. Most importantly, the congestion index developed here is based on data which are readily available. We compare our index to others based on Highway Performance Monitoring System (HPMS) data, and illustrate similarities and differences. We also discuss important issues for future research and data collection efforts which can contribute to more refined congestion measurement.

Transit-Oriented Development in San Diego County: Incrementally Implementing a Comprehensive Idea

Tue, 1 Nov 2022 00:00:00 +0000

While transit-oriented development (TOD) has become an increasingly popular planning idea, very few studies have examined how localities plan for and implement transit oriented projects. This paper helps fill that gap by studying the TOD implementation process near stations on the oldest of the current generation of light rail lines – the San Diego Trolley. Interviews with planning directors in the region, supplemented by zoning data, archival research, and inspection of station-area land use, all suggest that TOD is a niche market in the region. There are several barriers which have constrained TOD implementation in San Diego County. TOD projects have been pursued most aggressively in cases where those barriers are less severe or do not apply. Overall, we argue that each city, while being sympathetic to regional rail goals, works within a framework of local goals and constraints. The net result is regional TOD implementation which resembles the incremental model of policy-making...

Can HOT Lanes Encourage Carpooling? A Case Study of Carpooling Behavior on the 91 Express Lanes

Tue, 1 Nov 2022 00:00:00 +0000

This paper is a case study of carpooling behavior on the 91 Express Lanes. The 91 Express Lanes are the nation's first implementation of High Occupancy/Toll (HOT) lanes where carpools with three or more passengers could use the lanes for free (at the time the data for this study was collected) and others pay a toll that varies by time of day to use the premium Express Lane. One concern over such a policy is that people won't carpool if they can just pay for the travel time savings that they would normally obtain by carpooling and using a High Occupancy Vehicle (HOV) lane. Our survey data show that the rate of carpooling did not change much between the opening of the Express Lanes and now, there is a lot of changing between modes (increases and decreases in the number of passengers), there are a large number of people that carpool a few times a week, and that HOV-2s use both the regular lanes and the Express Lanes. We further investigate whether HOT lanes encourage carpooling by...

Urban Spatial Structure

Tue, 1 Nov 2022 00:00:00 +0000

In this essay we offer a view of what economics can say about and learn from urban structure. In doing so, we reach into neighboring disciplines; but we do not aspire to a complete survey even of urban economics, much less of the related fields of urban geography or urban planning. Our focus on internal structure should provide Mayor Daley a more complete basis for comparing Chicago's density to that of New York, or its degree of centralization to that of Los Angeles. (Throughout this essay we use the word "city," or the name of a particular city, to mean an entire urban region; other terms with similar meanings are "metropolitan area" and "urban area.")

Greenhouse Gas Emissions and Australian Commuters' Attitudes and Behaviour Concerning Abatement Policies and Personal Involvement

Tue, 1 Nov 2022 00:00:00 +0000

Public interest in the environment is building as we gain information about the deterioration in air quality and the potential threat of global warming. This research addresses the dichotomy between an individual's behavior and his or her attitudinal support for policies which are promoted as benefiting the environmental. We study how responses to attitudinal survey questions are interrelated, and how such responses are related to actual travel behavior using data from a survey undertaken in six capital cities in Australia in 1994. A measurement model is used to establish a set of latent attitudinal factors, and these factors are related in a structural equations model to a set of behavioral variables representing commuter's mode choice and choice of compressed work schedules, conditioned by a set of exogenous variables. Individuals with a strong environmental commitment are more likely to be female, from smaller households with fewer cars, be either under 30 years old or over...

Multiple Imputation Methodology for Missing Data, Non-Random Response and Panel Attrition

Tue, 1 Nov 2022 00:00:00 +0000

Modern travel-behavior surveys have become quite complex; they frequently include multiple telephone contacts, travel diaries, and customized stated preference experiments. The complexity and length of these surveys lead to pervasive problems with missing data and non-random response biases. Panel surveys, which are becoming common in transportation research, also suffer from non-random attrition biases. This paper shows how Rubin's (1987a) multiple imputation methodology provides a unified approach to alleviating these problems.

Before discussing solutions to problems caused by missing data and selection, it is important to recognize that their presence causes fundamental problems with identifying models and even "simple" population estimates. Section 2 reviews this work and stresses the need to make generally untestable assumptions in order to carry out any inference with missing data.

Chaining Behavior in Urban Tripmaking: Interim Report