Are We Done Fighting Traffic? Planning Congestion Resilient Regions
Urban Studies and Planning
Congestion alleviation has long been a core planning objective in most transportation programs, but existing policy portfolios have been both costly and unsuccessful at alleviating congestion. Road gridlock is inconvenient, but it remains unclear under which conditions this indicator of active urban places also impedes other social objectives, among which this dissertation focuses on the economy. This dissertation contributes by estimating congestion's economic drag and identifying how policy can contribute to high-functioning regions despite congestion. First, I use panel data for 88 U.S. Metropolitan Statistical Areas (MSAs) to estimate congestion's drag on employment growth (1993 to 2008) and productivity growth (2001 to 2008). Next, to identify "better" regional adaptations to congestion, I explore congestion resilience using a metric of economic growth per unit "cost" of congestion growth. Using panel data for 88 MSAs, I estimate the relative contributions of policies in enabling congestion resilience. Finally, using case studies of high-congestion MSAs, I explore policies distinguishing congestion resilient Los Angeles and Washington, DC from congestion unresilient Chicago and Houston. Results indicate that higher congestion is not associated with slower productivity growth, but is associated with slower employment growth rates above congestion levels of 39 (shorter-term) or 57 annual hours of delay per commuter (longer-term). When pooling MSAs across the range of congestion levels using panel data, sources of congestion resilience parallel "good" economic policy, more generally. But when focusing on four high-congestion MSAs, results suggest an important role for planners. Road transportation policy, public transit policy, and urban spatial structure distinguish congestion resilient Los Angeles and Washington, DC from congestion unresilient Chicago and Houston. In conclusion, evidence suggests that regional economies are highly adaptive to congestion and that planning policy can contribute to congestion resilience, particularly for high-congestion MSAs, but that context matters. Lessons from case studies of high-congestion MSAs are critical for other large and congested MSAs, but are less applicable across the spectrum of lower regional congestion levels. In fact, lessons from panel models including MSAs with a large-range of regional congestion levels indicate that congestion resilience is largely a function of "good" economic policy generally for most regions.