Subways, Strikes, and Slowdowns: The Impacts of Public Transit on Traffic Congestion

After recent debates about BART strikes, I found this paper from Michael Anderson to be pretty interesting.

Transit accounts for only 1% of U.S. passenger miles traveled but attracts strong public support. Using a simple choice model, we predict that transit riders are individuals who commute along routes with the most severe roadway delays. Their choices thus have high marginal impacts on congestion. We test this prediction with data from a strike by Los Angeles transit workers. Estimating an RD design, we find that average highway delay increases 47% when transit service ceases. This effect is consistent with our model’s predictions and many times larger than earlier estimates, which have concluded that transit provides minimal congestion relief.

traffic

He concludes with an interesting but perhaps short run argument about infrastructure investment:

Using a simple choice model, we show that transit provision should have much larger impacts on traffic congestion than predicted by models that do not incorporate within-city heterogeneity in driving delays. Our regression discontinuity estimates of the effects of a transit strike confirm this prediction, and back-of-the-envelope calculations suggest that the congestion relief externality of a peak-hour transit passenger mile ranges from $1.20 to $4.10. The lower bounds on potential long-run benefits are at least half those values. Contrary to the conclusions in the existing transportation and urban economics literature, the congestion relief benefits alone may justify transit infrastructure investments. 

 

Advertisements

About ozidar

I'm an Assistant Professor of Economics at the University of Chicago Booth School of Business and a Faculty Research Fellow at National Bureau of Economic Research. You can follow me on twitter @omzidar. http://faculty.chicagobooth.edu/owen.zidar/index.html
This entry was posted in Uncategorized and tagged , , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s