No abstract

Traffic congestion alleviation has long been a common core transport policy objective, but it remains unclear under which conditions this universal byproduct of urban life also impedes the economy. Using panel data for 88 US metropolitan statistical areas, this study estimates congestion’s drag on employment growth (1993 to 2008) and productivity growth per worker (2001 to 2007). Using instrumental variables, results suggest that congestion slows job growth above thresholds of approximately 4.5 minutes of delay per one-way auto commute and 11,000 average daily traffic (ADT) per lane on average across the regional freeway network. While higher ADT per freeway lane appears to slow productivity growth, there is no evidence of congestion-induced travel delay impeding productivity growth. Results suggest that the strict policy focus on travel time savings may be misplaced and, instead, better outlooks for managing congestion’s economic drag lie in prioritising the economically most important trips (perhaps through road pricing) or in providing alternative travel capacity to enable access despite congestion.

This study used data from www.walkscore.com to assess walking behavior in four U.S. cities. Walk scores measuring the so-called walkability of neighborhoods are ubiquitous, and although the relationship between walk scores and real estate values has been established, the relationship between walk scores and walking has not. In this research three models were developed to understand the correlation between walk scores (as indicators of walkability; i.e., opportunity to walk) and walking. The models looked at walk scores and walk mode share for different trip types. What changes should be expected with changing walk scores along different parts of the walk score spectrum are illustrated. Results suggest that walk scores may be used as a reasonable heuristic to assist with assessing trip impacts for individual projects. With the universal availability of such data, planners can establish a consistent, cost-effective tool for assessing walking behavior with robust and transferable results.