Travel Behavior

Growing poverty in America’s suburbs challenges their image as single-family residential communities for middle class, predominantly white families. Research shows that suburban areas now have the largest share of households under the poverty line. Since these areas have lower density development and lower levels of public transit service compared to urban areas, living in the suburbs may pose accessibility challenges for low-income households, particularly those without a personal vehicle. To explore housing and transportation issues associated with the suburbanization of poverty, we...

A multi-lane traffic flow model realistically captures the disruptive effects of lane- changing vehicles by recognizing their limited ability to accelerate. While they accelerate, these vehicles create voids in the traffic stream that affect its character. Bounded acceleration explains two features of freeway traffic streams: the capacity drop of freeway bottlenecks, and the quantitative relation between the discharge rate of moving bottlenecks and bottleneck speed. The model com- bines a multilane kinematic wave module for the traffic stream, with a detailed constrained-motion model to...

Employer-provided private shuttles have become a prominent part of the transportation network between San Francisco and Silicon Valley. As the Bay Area plans for transportation investments to meet sustainability goals and accommodate future population and employment growth, an understanding of the role of regional commuter shuttles becomes increasingly important. This study investigates the impacts of private shuttles on commute mode and residential location choice by conducting a travel time comparison and surveying shuttle riders. The authors find that the provision of shuttles and...

Urban planners are increasingly concerned about the sprawling suburban development in metropolitan areas around the world, which they often blame for growing traffic congestion and excessive highway investment needs. This dissertation seeks to shed light on this issue by studying the relationship between morning commute congestion and urban form. The causes and consequences of traffic congestion have been extensively studied in the economics and engineering literatures. Unfortunately, most conclusions have been drawn from very idealized models, which either fail to consider adequately the...