Reihan Salam @ NRO picks on Transportation Costs Too Much (and Is transport too expensive): Spending More for Less: The Case of U.S. Infrastructure and points me to:
Brad Plumer @ The Washington Post Are America’s subways and roads overpriced? [I was cited in the Washington Post (online), and no-one tells me]
Alon Levy @ Pedestrian Observations on The CAHSR Bombshell
Also worth noting is John Bedell's blog riffing on Plumer: Why Does Infrastructure Cost So Much in the US?