working paper

Gender Differences in Commuting: An Empirical Study of the Greater Los Angeles Metropolitan Area

Publication Date

December 31, 1993

Author(s)

Abstract

Since the nineteen-seventies, as a byproduct of our rapidly changing social structure, gender equity has become a major concern. This concern and the increase in the female labor force participation rate and in the female commuting population has motivated scholars to analyze and explain male and female commuting differences. Despite the many studies of gender-based differences in commuting behavior over the past decade, scholars still have not been able to agree on the reasons males commute longer distances than females. A general consensus, except for the concerns of Gordon, Kumar and Richardson (1989), is that socioeconomic and spatial structures constrain females more than males, resulting in women having shorter commuting than males. With regard to socioeconomic constraints, the first thorough examination of those factors which possibly affect gender differences in commuting was done by Hanson and Johnston (1985). Later, the effect of household type was examined by Johnston-Anumonwo (1992) using the same data used by Hanson and Johnston (1985).

Phd Dissertation

Dynamic discrete demand modeling of commuter behavior

Publication Date

December 31, 1993

Author(s)

Abstract

The level and extent of demand for a transportation service, including the determinants of the demand, can be meaningfully analyzed only by incorporating their evolution over time. Since most travel demand models are based on cross-sectional data, longitudinal analytic methods need to be developed for the study of travel behavior. Heterogeneity and non-stationarity of behavior, lagged effects, and effect of time varying variables are other factors that require using dynamic modeling techniques. A dynamic beta-logistic model using a panel data set of approximately 2,200 Southern California commuters was developed to fulfill this need. Waves 1, 5, and 8 of this panel, which encompasses a period beginning February, 1990 to February, 1993 was used. Seventy five percent of Waves 1 and 5 data were randomly sampled for model development. The remaining 25 percent as well as the data from Wave 8 were used in model validation. The model had a successful prediction rate of about 98.6% for the two two-wave periods between Waves 1 and 5 and between Waves 5 and 8. Policy simulations were carried with Waves 5 and 8 data. For policy simulation, the impact on ride-sharing of reserved parking, cost subsidy, and guaranteed ride home incentives were studied. An increase of over 100% in the usage of shared-ride mode in Waves 5 and 8 was predicted when all respondents were simulated to have perceived a set of three incentives in both waves. This increase in the shared-ride alternative corresponded to a decrease of over 42% in the usage of the drive-alone modes in both waves. There was a decrease of about 35% in the drive-alone alternative when the three incentives were perceived by all commuters only in Wave 5. If the three incentives were perceived by all commuters in Wave 8 only, the drop in solo-driving in the two-wave period was only 7.1%, which demonstrates the existence of lagged and delayed effects in travel behavior. Of the three incentives guaranteed ride home induces the biggest reduction in the use of the drive-alone alternative.

working paper

State and National VMT Estimates: It Ain't Necessarily So

Publication Date

December 31, 1993

Author(s)

Abstract

The enormous jump in vehicle miles traveled (VMT) reported by the 1990 U.S. Nationwide Personal Transportation Survey (NPTS) 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.

This paper re-analyses the NPTS data and shows that the VMT jump was a statistical error. The 1990 NPTS oversampled new vehicles and undersampled old ones. Since new vehicles are driven two to three times as much as old one, the sampling bias will overestimate VMT. And the result may have been intensified by an underestimate of VMT in the 1983 NPTS, thus increasing the apparent jump form 1983 to 1990.

I also calculate alternative VMT estimates using data from two other national surveys and a massive odometer-based California study. The three new estimates are in close agreement with each other. I conclude that VMT per vehicle actually grew at only half the rate estimated by the NPTS.

working paper

Population and Employment Densities: Structure and Change

Publication Date

December 31, 1993

Abstract

We examine spatial patterns and their changes during the 1970s for the Los Angeles region, by estimating monocentric and polycentric density functions for employment and population. Downtown Los Angeles is clearly identified as the statistical monocentric center of the region, and it is the most consistently strong center in the polycentric patterns. Polycentric models fit statistically better than monocentric models, and there was some shift in employment distribution toward a more polycentric pattern. These findings verify the existence of polycentricity in Los Angeles and demonstrate for the first time that employment and especially population follow a polycentric pattern based on exogenously defined employment centers. The results confirm that both employment and population became more dispersed during the 1970s.

working paper

Does Generalizing Density Functions Better Explain Urban Commuting? Some Evidence from the Los Angeles Region

Publication Date

December 31, 1993

Author(s)

Abstract

The assumption that urban workers economize on commuting is implicit in urban economic theory. Yet it has been challenged by some recent studies. This paper estimates commute flows implied by three urban density functions: monocentric, polycentric, and dispersive. It finds that an urban density function better predicting the actual spatial patterns also better explains the actual commuting behavior. This finding helps us to preserve the assumption that urban workers make attempts to economize on commuting in their location choices.

conference paper

Commuting Stress, Ridesharing, and Gender: Analyses from the 1993 State of the Commute Study in Southern California

Publication Date

December 31, 1993

Author(s)

Abstract

A stressful nature of exposure to traffic congestion in automobile commuting has been demonstrated in previous quasi-experimental research that has been measurement-intensive but conducted with relatively small samples. The present study examined commuting stress in automobile travel with a large representative sample (N = 2591) in southern California through telephone survey. Commuting stress was found to be significantly associated with distance and duration of the commute, controlling for age and income. As predicted, the stressful effects of long distance commutes (> 20 miles) were further moderated by gender, as women in such commutes perceive much greater commuting stress spillover to work and home. Some hypothesized stress-mitigating effects of ridesharing were found, as full-time ridesharers were significantly less bothered by traffic congestion and more satisfied with their commutes than solo drivers. In analyses of prospective adoption by solo drivers of alternative commuting modes, it was found that the perception of one’s commute as having a negative impact on family life had a very significant effect on the inclination to try carpooling and train/rail, beyond the effect associated with distance itself. Commuting stress is discussed as an external cost of traffic congestion that is internalized by the solo driver. Marketing strategies for alternative modes of commuting might increase their effectiveness by highlighting stress consequences, especially negative impacts on family life. 

working paper

Governmental Failures in Evaluating Programs

Publication Date

December 31, 1993

Author(s)

Abstract

Consider a government that adopts a program, sees a noisy signal about its success, and decides whether to continue the program. Suppose further that the success of a program is greater if people think it will be continued. This paper considers the optimal decision rule for continuing the program, both when government can and cannot commit. We find that welfare can be higher when information is poor, that government should at times commit to continuing a program it believes had failed, and that a government which fears losing power may acquire either too much or too little information.

working paper

Did the 65 mph Speed Limit Save Lives?

Publication Date

December 31, 1993

Author(s)

Abstract

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 change 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.

working paper

Gender Differences in Commuting: An Empirical Study of the Los Angeles Metropolitan Area

Publication Date

December 31, 1993

Author(s)

Abstract

In sum, my results show that household type, race and housing tenure influence males and females differently. I find that the presence of children contributes to the gender difference in commuting more for whites and for two-worker households than for other groups. However, the effects of the presence of children are not significant on both male and female commuting distances. In fact, I find that two-worker household males behave differently from two-worker household females, and that two-worker household females behave differently from single-worker household females. I also find that there are sharper gender differences among whites than among nonwhites, a conclusion similar to that of Mclafferty and Preston (1991). Finally, I find that housing tenure seems to strongly influence the commuting distances of males, nonwhites, and workers from two-worker households.

working paper

Smart Corridor Evaluation Plan: Conceptual Design

Publication Date

December 31, 1993

Author(s)

Gen Giuliano, James Moore, Martin Wachs

Abstract

This report presents the Conceptual Design Plan for evaluating the effectiveness of the Smart Corridor Demonstration Project. The specific objectives of this report are to: 1) develop a conceptual structure for the Smart Corridor evaluation, 2) define evaluation data requirements and collection procedures, and 3) select and/or develop data reduction and data analysis methodologies. Overall, the Smart Corridor is designed to obtain improved utilization of existing roadway facilities, both freeway and arterial, through the use of Advanced Traveler Information Systems ( ATIS) and Advanced Traffic Management Systems (ATMS), through improved inter-agency coordination, and through better use of conventional traffic management strategies.