Mobility and Congestion in World Cities: Evidence from Google Maps
Prottoy Akbar, University of Pittsburgh
Victor Couture, University of British Columbia
Gilles Duranton, University of Pennsylvania and NBER
Adam Storeygard, Tufts University and NBER
Effects of Pavement Roughness on Traffic Outcomes: Evidence from California
Brad R. Humphreys, West Virginia University
Margaret Bock, West Virginia University
Alexander J. Cardazzi, West Virginia University
Can Behavioral Interventions Be Too Salient? Evidence From Traffic Safety Messages
Jonathan Hall, University of Toronto
Joshua Madsen, University of Minnesota

Behavioral interventions are a popular tool for encouraging socially desirable behavior and are expressly designed to seize people's attention. However, little consideration has been given to the costs of seizing attention. Hall and Madsen estimate these costs in the context of an increasingly common highway traffic safety campaign that displays roadside fatality counts on highway dynamic message signs (DMSs). They exploit detailed data on DMS and crash locations, DMS log files, and a unique setting in Texas where fatality messages are shown only during one week each month. Hall and Madsen find that this behavioral intervention significantly increases the number of traffic crashes. The increase in crashes is immediate, dissipates over longer distances, and increases with the displayed fatality count. Furthermore, drivers do not habituate to these messages, even after five years, and the effects do not persist beyond the treated weeks. Crashes increase statewide during treated weeks, inconsistent with any benefits. Their results show that behavioral interventions, designed to be salient, can crowd out more important considerations, causing interventions to backfire with costly consequences.

Traffic in the City: The Impact of Infrastructure Improvements in the Presence of Endogenous Traffic Congestion
Treb Allen, Dartmouth College and NBER
Costas Arkolakis, Yale University and NBER
The Value of Time: Evidence from Auctioned Cab Rides
Nicholas Buchholz, Princeton University
Laura Doval, California Institute of Technology
Jakub Kastl, Princeton University and NBER
Tobias Salz, Massachusetts Institute of Technology and NBER

Buchholz, Doval, Kastl, and Salz recover valuations of time using detailed data from a large ride-hail platform, where drivers bid on trips and consumers choose between a set of rides with different prices and waiting times. They estimate demand as a function of prices and waiting times and find that price elasticities are substantially higher than waiting-time elasticities. The researches show how these estimates can be mapped into values of time that vary by place, person, and time of day. Buchholz, Doval, Kastl, and Salz find that the value of time during non-work hours is 16%lower than during work hours. Most of the heterogeneity in the value of time, however, is explained by individual differences. They apply our estimates to study optimal time incentives in highway procurement. Standard industry practices, which set incentives based on a uniform value of time, lead to mis-priced time costs by up to ninety percent.

Does the US have an Infrastructure Cost Problem? Evidence from the Interstate Highway System
Neil Mehrotra, Federal Reserve Bank of New York
Matthew Turner, Brown University and NBER
Juan P. Uribe, Brown University

Between 1990 and 2008 the cost to construct a lane mile of interstate increased five-fold while the cost of resurfacing doubled. We consider four explanations for these increases: composition; changes in pavement durability; the institutional and regulatory environment; and input prices. Only changes in input prices explain the increase in resurfacing costs. None of the explanations is clearly responsible for the increase in the cost of new construction, but the data suggest hard to observe changes in how highways are built. This suggests a that a cost disease affects at most the 34% of the interstate highway budget devoted to construction. A calibrated model of optimal highway capital accumulation does not suggest a dramatic increase in the user cost of interstate capital per vehicle mile travelled.


Below is a list of conference attendees.
Tanweer Akram, General Motors
Mona Asudegi, Department of Transportation
Margaret Bock, West Virginia University
Ted Boll, U.S. Department of Transportation
Valentin Bolotnyy, Stanford University
Margaret Brissenden, Harvard University
Elaine Buckberg, General Motors
Alexander J. Cardazzi, West Virginia University
Qianmiao Chen, University of California at Berkeley
Tony Choi, U.S. Department of Transportation
Adriano Costa, Massachusetts Institute of Technology
Lindsey Currier, Harvard University
Yael Elster, Harvard University
Timothy Fitzgerald, Texas Tech University
Felix L. Friedt, Macalester College
Diana Furchtgott-Roth, Department of Transportation
Diana Galperin, Environmental Protection Agency
Reed Garfield, U.S. Department of Transportation
Julian A. Gomez-Gelvez, University of Maryland
Tracy Gordon, The Urban Institute
Jiemin Guo, Bureau of Economic Analysis
Jonathan Hall, University of Toronto
Brad R. Humphreys, West Virginia University
Parastoo Jabbari, University of Washington
Dan Kraynak, University of Maryland
Ken Leonard, U.S. Department of Transportation
Jing Li, Massachusetts Institute of Technology
Berin Linfors, Department of the Census
Joshua Madsen, University of Minnesota
Marquise J. McGraw, American University
Jeremy J. Michalek, Carnegie Mellon University
Evan Michelson, Alfred P. Sloan Foundation
William Mockovak, Bureau of Labor Statistics
Alejandro Molnar, The World Bank
Charles E. Noble, University of Minnesota
Krisztina Orban, NBER
David Pace, U.S. Department of Transportation
Don Pickrell, Department of Transportation
Steven Pierson, American Statistical Association
Steve Poftak, Massachusetts Bay Transportation Authority
Steven Polzin, US Department of Transportation
Luis E. Quintero, Johns Hopkins University
Sari Radin, U.S. Department of Transportation
Eric Ragan, U.S. Department of Transportation
Simon Randrianarivelo, Bureau of Transportation Statistics
Erick Sager, Federal Reserve Board
Ian Savage, Northwestern University
Tomas Serebrisky, Inter-American Development Bank
Chang Shen, University of Maryland
Chad Shirley, Congressional Budget Office
Mark Steinmeyer, Smith Richardson Foundation
Anjana Susarla, Michigan State University
Tobias A. Sytsma, University of Oregon
Darren Timothy, Department of Transportation
Juan P. Uribe, Brown University
Jacob Ward, Department of Energy
Asa Watten, Michigan State University
Ermias Weldemicael, U.S. Department of Transportation
Harry Wheeler, University of California at Berkeley
Bingxin Yu, Department of Transportation
Michael Yu, Johns Hopkins University
Yichen Christy Zhou, Clemson University
Mary Zimmerman, Department of Transportation



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