Sovereign immunity bars claim arising from highway construction, as the private right of action in the Act exists only to enforce the Act, not to challenge the program-based decisions of the agency.
Federal court does not have jurisdiction over a breach of contract suit against a state unless the claim states a disputed and substantial federal issue, and prudential factors are favorable.
http://media.ca1.uscourts.gov/pdf.opinions/17-1951P-01A.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.