Charles Lave

A DISAGGREGATE MODEL OF AUTO-TYPE CHOICE

Previous models of auto-type choice have not been able to disentangle very much of the structure of the households auto-choice decision: the models assumed that very few auto characteristics affect choice, and often these few parameters were estimated with low precision. Hence the models had only limited use in forecasting the effects of government policies to influence transportation energy consumption. The present paper introduces a multinomial logit model for the type of car that households will choose to buy. The model includes a large variety of auto characteristics as explanatory variables, as well as a large number of characteristics of the household and the driving environment. The model fits the data quite well, and all of the variables enter with the correct signs and plausible magnitudes.

Did the 65 mph Speed Limit Save Lives

In 1987, most states raised the speed limit from 55 to 65 mph on portions of their rural interstate highways. There was intense debate about the increase, and numerous evaluations were conducted afterwards. These evaluations share a common problem: they only measure the local effects of the change. But the change must be judged by its system-wide effects. In particular, the new 65 mph limit allowed the state highway patrols to shift their resources from speed enforcement on the interstates to other safety activities and other highways--a shift many highway patrol chiefs had argued for. If the chiefs were correct, the new allocation of patrol resources should lead to a reduction in statewide fatality rates. Similarly, the chance to drive faster on the interstates should attract drivers away from other, more dangerous roads, again generating system-wide consequences. This study measures these changes and obtains surprising results. We find that the 65 mph limit reduced statewide fatality rates by 3.4% to 5.1%, holding constant the effects of long-term trend, driving exposure, seat belt laws, and economic factors.

Performance indicators for transit management

Transit performance can be evaluated through quantitative indicators. As the provision of efficient and effective transit service are appropriate goals to be encouraged by federal and state governments, these goals are used to develop performance indicators.Three efficiency and four effectiveness indicators are described, together with two overall indicators. These nine indicators are analyzed for comparability utilizing operating and financial data collected from public transit agencies in California.Performance indicators selected for this study should not be viewed as final. Twenty-one performance indicators proposed by previous studies were reviewed. Theoretical considerations and unavailability or unreliability of data caused omission of several useful measures like passenger-miles. Circumstances such as improved data, emphasis upon goals other than efficiency and effectiveness, and local conditions might warrant the inclusion of indicators deleted from this research.

The Demand Curve Under Road Pricing and the Problem of Political Feasibility

Road pricing is widely advocated as a solution to congestion problems. The underlying theory is well developed, and we even have the technology to implement it without toll booths. Only political barriers remain: Decision makers are reluctant to retrofit tolls on existing highways because they do not know what circumstances might make such an action acceptable to the public. This paper develops a graphical model that displays the interaction between road capacity, user demand, travel speed and toll charges. The model is then used to analyze the sources of public resistance to road pricing. Might the potential response to road pricing be predicted using data from the new toll roads now being built around the United States? Our model shows it cannot: Political success depends on the demand characteristics at the right-hand side of the demand curve, while toll road data only trace out the left-hand side of the curve. Our model also shows situations where the new toll roads are likely to generate public anger. The Appendix discusses an experimental design that uses unobtrusive measures to assess the effect of a transportation project.

Measuring the Decline in Transit Productivity in the U.S

Starting in the mid-1960s, US government policy encouraged the public takeover and subsidy of what had been a self-supporting, privately owned transit industry. The combination of public ownership and subsidy halted the long-term decline in ridership, but it also led to the growth of an enormous financial deficit. Using individual data from 62 transit properties to measure the change in productivity (output per dollar of input) over the period 1950-1985, this paper examines the relationship between productivity and government subsidies. The magnitude of the productivity decline surprising: indeed, if productivity had merely remained constant since 1964, the year the subsidy program began, total operating expenses would be more than 40% lower. To put that figure in perspective, this is enough cost reduction to erase most of the current operating deficit -- without raising fares.

MARKET SHARE OF IMPORTED CARS: A MODEL OF GEOGRAPHIC AND DEMOGRAPHIC DETERMINANTS

Abstract This study models the market penetration of imported cars using two diverse data bases, 1975 State aggregates and 1978 individual households, using both linear and nonlinear estimation techniques. All of the major results replicate across the different data bases and the different estimation techniques. A model of import market shares is obviously of interest in its own right, and it is also of interest for what it says about the reasons why people buy small, fuel efficient cars in general, whether they are imported or domestic. The major explanatory factors found are proximity to the east or west coast, and a variety of family characteristics, principally education and number of vehicles owned; all of which exert a positive influence on the probability of buying an imported car. After exploration of a number of alternative explanations, it is tentatively concluded that the coastal-nearness variables are acting as proxies for the variation in manufacturers marketing effort between states.

Effect of the 65 m.p.h. speed limit on highway safety in the U.S.A. (with comments and reply to comments)

Since April 1987, 40 states have increased their speed limits on rural Interstate highways to 65 m.p.h. Motorists have responded by driving faster on these highways and some evidence suggests they are driving faster on highways without a change in speed limits as well. Both the average speed and the 85th percentile in speeds has increased on roads posted at 65 m.p.h. Various statistical approaches for estimating the effect of these higher speeds indicate that fatalities on highways posted at 65 m.p.h. were 15 to 25% higher than expected in 1988.

REGULATION BY PRICES AND BY COMMAND.

Standard economic theory states that regulation by price is more efficient than regulation by command and control. Exceptions may arise if regulators have good knowledge of the supply curve. In practice, though, governments usually regulate by command and control and do so when there is uncertainty about the technology of supply. We show that government may prefer to regulate by command and control when it cares about the investment decisions of a firm.

WHAT REALLY IS THE GROWTH OF VEHICLE USAGE

The enormous jump in vehicle miles traveled (VMT) per person reported by the 1990 Nationwide Personal Transportation Survey (NPTS) conducted by the U.S. Census Bureau caused a great deal of concern among planners and policy analysts. Such a jump seemed to portend an era of ever-increasing travel, pollution, and energy consumption. Three alternative VMT estimates are developed using data from other national surveys and a massive odometer-based California study. The three new estimates are nearly identical but differ markedly from the NPTS results. (Reanalysis of the 1990 NPTS shows that it oversampled new vehicles: since new vehicles are driven two to three times as much as old ones, VMT per average vehicle is overestimated.) VMT per vehicle actually grew at only half the rate estimated by the NPTS.

The high cost of a bargain: Winning the right to use part-time transit drivers

Abstract Over the past decade most transit districts have gained the right to use part-time drivers. The change was strongly opposed by their unions and required substantial contract concessions on other issues to win union consent. This paper estimates the cost of these concessions: how much did transit management pay for the right to use part-time labor? It appears the cost was very large: during the early period of the innovation (1978–1981) the “give-backs” necessary to win labor consent were probably as large as, or larger than, the financial gains from use of part-time labor. Furthermore, these initial bargaining costs have carried over into subsequent contracts. In contrast, the transit agencies that adopted part-time labor in 1982–1983 paid a much lower cost, probably zero. The study is based on cross-section regression analyses of data from 1979, 1981, and 1983. Each regression estimates the effects of a series of part-time labor dummy variables while holding constant the effects of agency size and the general wage level in the operating area.