“Transit PPPs tend to create institutional mish-mash  in the U.S.,” says Michael Schneider, a consultant to LA Metro and other transit agencies evaluating private financing and life-cycle benefits. “It’s very complex to undertake a rail PPP unless you plan it right from the beginning, and it does not interface with or have an impact on other lines,”  says Schneider, a principal at HDR/Infraconsult.

There are few U.S. projects which meet that criteria, he says, so transit PPPs are relatively rare. The $2-billion Denver Eagle PPP worked as a DBFOM concession in 2010, but for specific reasons: