Peer reviewed studies and the transit referendum

This is a copy of a comment I’ve left at Northern Insights, which is pending approval, in response to this post:

Speaking of without evidence, I note you’ve been pressed a number of times on Twitter to provide links to the studies above. I believe I may be able to help you here, with at least with 2 of those:

The Fundamental Law of Road Congestion: Evidence from US cities
By Gilles Duranton and Matthew A. Turner September 08, 2009

Evaluating Public Transit Investment in Congested Cities∗
Justin Beaudoin, Y. Hossein Farzin and C.-Y. Cynthia Lin November 27, 2014

I’d like to highlight some passages from them:


The fact that increases in public transit do not reduce traffic does not imply that such improvements are not in the public interest. While we are not able to perform a welfare calculation to evaluate extensions to bus based public transit, we suspect on the basis of earlier research (Kain, 1999, Duranton and Turner, 2008) that improvements to bus-based public transit are often welfare improving.

Together, these findings strengthen the case for congestion pricing as a policy response to traffic congestion.


Overall, our analysis indicates that the congestion-reduction effects of public transit supply warrant a higher level of public transit investment than would be provided on the basis of the isolated valuation of public transit ridership; this effect would be larger still if the additional negative externalities of auto travel were incorporated into this framework.

“Expanding transit and subsidizing fares has limited impacts on automobile congestion, given relatively modest own-price elasticities for transit… Nonetheless, urban transit fares are heavily subsidized…Improving service quality (e.g. increasing transit speed, reducing wait times at stops, and improving transit access) may be more effective in deterring automobile use.

While there is modest evidence that public transit’s reputation as a ‘green’ policy instrument is justified, the results also reaffirm the theoretical and empirical argument that traffic congestion can only be adequately addressed by devising economically and politically accepted approaches to efficiently pricing auto travel across the U.S.

I think one can be forgiven into thinking that perhaps the reason you haven’t provided links to these reports is they don’t really say, particularly the UC-Davis study, what you say they do.

But more importantly, I think you might be hesitant because both endorse road pricing.

Which is, in fact, in the Mayor’s Plan.

The Mayors’ Council is committed to implementing a more consistent region-wide approach to pricing road usage as the most fair and effective way to reduce congestion.

To tackle congestion and to make sure that the significant new road capacity we have added in this region doesn’t soon get swallowed up in traffic jams, there is only one tool that has a proven track record. It’s the tool that we use to allocate scarce resources everywhere else in the economy: pricing.

Maybe the missing World Bank study (the one’s I’ve found actually endorse public transit investment in specific cities – link available upon request) provides a strong case against transit investment. But in terms of these two studies, both actually significantly undermine your case.