Thursday, March 28, 2013

Public transit in LA (again)

I have for many years been pessimistic about rail transit -- especially for LA.  There have been many others.  Baum-Snow and Kahn (Brookings, 2005) studied 1970-2000 public transit trends for major U.S. cities.  They found that the seven U.S. cities with rail in 1970 experienced average transit use decline of 5% (over 30 years); the fourteen U.S. cities that added rail in 1970-2000 experienced average change of zero (30 years); all U.S. MSAs with no rail experienced average decline of 1% (30 years); all U.S. MSAs also experienced average decline of 1% (30 years).

But Paul Kruman blogs that "Subways Pay".  He points readers to a new paper by Michael L. Anderson.  Here is the abstract:
Public transit accounts for only 1% of U.S. passenger miles traveled but nevertheless attracts strong public support. Using a simple choice model, we predict that transit riders are likely to be individuals who commute along routes with the most severe roadway delays. These individuals’ choices thus have very high marginal impacts on congestion. We test this prediction with data from a sudden strike in 2003 by Los Angeles transit workers. Estimating a regression discontinuity 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 generally concluded that public transit provides minimal congestion relief. We find that the net benefits of transit systems appear to be much larger than previously believed.
In light of this evidence, LA rail transit, Anderson suggests, is actually cost-effective. The important part of the paper, in my view, is at the end where the author takes a long run view. Reactions to sudden strikes by transit workers are anomalous because people make it their business to find ways to adjust.  To model the longer run, Anderson relies on annual rail transit ridership growth of 0.9 million - 1.7 million.  I doubt it.  As my recent post (above) mentions, we just recently got back to 1985 transit use levels in LA.


NHTS 2009 reports that nationally 8.7% of U.S. households did not own a car (Table 17).  But the Los Angeles MTA reports that, of its rail riders, 35.6% came from households with no cars (Fig. 3.5).  That should cause us to wonder whether a transit strike can dump many rail users onto "routes with the most severe roadway delays."