So "how" is the feds giving Cintra the loans?
http://www.fhwa.dot.gov/ppp/tifiasep15.htm
Read this letter to The Federal Highway Administration applying for a federal loan from TXDOT. The read on down to the Experiment.
"Federal policies generally encourage price competition, which this concession procurement contemplates. However, we recognize that it would be burdensome for the TIFIA office to be required to work with multiple proposers during the bid preparation period, when ultimately TxDOT will award only one of them the contract"
So the state of Texas will borrow the money from the Feds and then give it to Cintra. This reminds me of "money laundering" Not kosher.
You might not think it's kosher, but the Federal government is loaning the money to Texas, and Texas must pay it back. There are plenty of conditions, but requiring Texas to choose one contractor over another is not the sort of federal intervention I'm willing to consider as beneficial.