Mubassira Khan

Potential crash reduction benefits of shoulder rumble strips in two-lane rural highways

This paper reports the findings from a study aimed at examining the effectiveness of shoulder rumble strips in reducing run-off-the-road (ROR) crashes on two-lane rural highways using the empirical Bayes (EB) before-and-after analysis method. Specifically, the study analyzed the effects of traffic volume, roadway geometry and paved right shoulder width on the effectiveness of shoulder rumble strips. The results of this study demonstrate the safety benefits of shoulder rumble strips in reducing the ROR crashes on two-lane rural highways using the state of Idaho 2001-2009 crash data. This study revealed a 14% reduction in all ROR crashes after the installation of shoulder rumble strips on 178.63miles of two-lane rural highways in Idaho. The results indicate that shoulder rumble strips were most effective on roads with relatively moderate curvature and right paved shoulder width of 3 feet and more.

Joint Household-Level Analysis of Individuals’ Work Arrangement Choices

This paper presents a comprehensive, multidimensional, multivariate binary probit model that can simultaneously represent multiple aspects of individuals’ work arrangement decisions while accounting for interactions between household members in individual employment-related choices. The model is estimated on the basis of a survey sample drawn from the San Francisco Bay Area, California, from which a rich set of accessibility measures is available to account for built environment influences on work-related decisions. Model results show that a host of demographic, socioeconomic, built environment, and attitudinal variables influence individual choices regarding work arrangements; more importantly, the model shows that there is much employment-related interaction among household members. The model can be used to predict the employment choices of individuals within larger microsimulation models of activity-travel demand.

The Impact of Land-Use Variables on Free-Floating Carsharing Vehicle Rental Choice and Parking Duration

Carsharing is an innovative transportation mobility solution, which offers the benefits of a personal vehicle without the burden of ownership. Free-floating carsharing service remains a relatively new concept and has gained popularity because it offers a flexible one-way auto rental option that charges usage by the minute. Traditionally, carsharing services require returning the rented vehicle to the same location where rented within a specified rental duration. Since free-floating service is a very new addition in the overall transportation system, the empirical research is still very limited. This study focuses on identifying the impact of land-use variables on free-floating carsharing vehicle rental choice and parking duration of car2go services in Austin, Texas on a typical weekday between the 9:00 AM and 12:00 PM off-hour period. Two different methodological approaches, namely a logistic regression model approach and a duration model technique are used for this purpose. The results of this study indicate that demographic variables, the carsharing parking policy, and the number of transit stops all affect the usage of free-floating carsharing vehicles.