The Shock Heard round the Suburbs: Assessing the Vulnerability, Resilience, and Transportation Affordability of Higher Fuel Price Scenarios

Abstract

With transportation the second highest household expenditure, understanding the disproportionate impact that a drastic increase in the gas price might have on a major city and region is vital. This study sought to increase the understanding of resiliency, vulnerability, and transportation affordability issues by asking the following questions: What would happen if the cost to drive suddenly doubled or tripled? Who would be better off and why? How much would residency near downtown or near one's job make a difference? What would matter in terms of transit infrastructure? How much of a role would current travel behavior play? This study derived resiliency scenarios in which the cost to drive increased one and one-half, two, and three times with the use of a multinomial logistic regression mode choice model developed with major travel surveys conducted in 1997 and 2008, a time period during which gas prices more than tripled. The focus of this study was on work trips, which were those trips most likely to be nondiscretionary. The annual cost to commute was estimated as a percentage of the median household income. Transit infrastructure, active transportation, built environment, land use, and socioeconomic status were assessed for their influences on resiliency, vulnerability, and transportation affordability. Although high income represented one path to resilience, the study results suggested that higher resilience could also be found in locations with proximity to high levels of employment, with more compact and connected street networks, and with better transit infrastructure. Beyond current travel behaviors, a significant option value to transit was also found in the resiliency scenarios. Transportation choice was found to create network redundancy and to facilitate adaptability under extreme conditions.