Contents lists available at ScienceDirect Journal of Transport Geography journal homepage: www.elsevier.com/locate/jtrangeo Is traffic congestion overrated? Examining the highly variable effects of congestion on travel and accessibility Andrew Mondschein a,⁎ , Brian D. Taylor b a Department of Urban and Environmental Planning, University of Virginia School of Architecture, Campbell Hall, PO Box 400122, Charlottesville, VA 22904-4122, United States b Institute of Transportation Studies, UCLA Luskin School of Public Affairs, 3250 Public Policy Building, Los Angeles, CA 90095-1656, United States ARTICLE INFO Keywords: Accessibility Congestion Travel behavior ABSTRACT Congestion is universally unpopular, but is it always a problem? Are some places more “congestion-adapted” than others? Using data for Los Angeles, we examine whether the geographies of congestion and accessibility are distinct by mapping and describing them across neighborhoods. We then estimate a series of regression models of trip-making to test the net effects of traffic delays on behavior. We find that there are places where people make many trips and engage in many activities despite lots of congestion, which tend to be more central, built-up areas that host many short trips; in other places, high congestion and low activity coincide. Why the variance? While congestion can constrain mobility and reduce accessibility, traffic is also associated with agglomerations of activity and is thus a byproduct of proximity-based accessibility. Whether agglomeration and congestion have net positive or negative impacts on activity participation thus varies substantially over space. Controlling for factors such as income and working at home, we find that the effects of congestion on access depend on whether congestion-adaptive travel choices (such as walking and making shorter trips to nearby destinations) are viable. Because “congestion-adapted” places tend to host more trip-making, planners may be justified in creating more such places in order to increase accessibility, even if doing so makes absolute levels of congestion worse in the process. 1. Introduction Traffic congestion is widely perceived as among the most vexing of urban ills – one that exacts high social, economic, and environmental costs on residents and firms alike. But is congestion really all it's cracked down to be? Perhaps not. Many urban and transportation planners assume that better land use and transportation integration will reduce congestion by promoting both compact development and alternatives to private vehicle travel. These efforts to increase walk- and transit-friendly environments in- clude increasing development densities, mixing land uses, and devoting more street space to support other than motor vehicle movements (Bogert et al., 2011; Ewing, 2008; Talen and Koschinsky, 2013; US Environmental Protection Agency, 2016). But while such urbanizing policies may increase travel choices, they typically increase traffic de- lays as well, and in many communities have occasioned visceral pushback from residents and the officials they elect over rising con- gestion levels (Downs, 2005; Obrinsky and Stein, 2007). But if these policies are successful at increasing the number and variety of nearby destinations accessible by foot, bike, bus, and car, trip-making and utility may well increase in spite of worsening congestion. To examine this issue, we assess the accessibility/congestion re- lationship using data for Los Angeles, one of the largest and most congested U.S. metropolitan areas. We find that some neighborhoods are more “congestion-adapted” than others by facilitating high levels of personal and economic activity across shorter distances and via non- auto modes, often in spite of high levels of congestion. In contrast, accessibility in other, less congestion-adapted areas may be strongly inversely related to congestion levels, which square with both intuition and the traditional tenets of transportation engineering practice. So while bumper-to-bumper traffic may be similarly frustrating to drivers everywhere, its social and economic effects likely vary substantially from place to place. While the concept of accessibility has gained considerable traction among urban and transportation scholars as a more meaningful mea- sure of how transportation systems enable social and economic activity, such measures are only beginning to trickle into professional trans- portation engineering and planning practice. This article examines how measures of accessibility may produce very different results than measures of delay. The common use of congestion measures that http://dx.doi.org/10.1016/j.jtrangeo.2017.08.007 Received 25 October 2016; Received in revised form 24 June 2017; Accepted 20 August 2017 ⁎ Corresponding author. E-mail addresses: mondschein@virginia.edu (A. Mondschein), btaylor@g.ucla.edu (B.D. Taylor). Journal of Transport Geography 64 (2017) 65–76 0966-6923/ © 2017 Elsevier Ltd. All rights reserved. MARK