Federal law is different.
The Surface Transportation Program can be used on Interstate, National Highway System, and all roads functionally classified by FHWA as other than local or rural minor collectors. The Congestion Mitigation and Air Quality Improvement Program is directed towards transportation projects which will contribute to Clean Air Act requirements in non-attainment areas for ozone and carbon monoxide. The Bridge Replacement and Rehabilitation Program is continued. The Interstate System is a part of the NHS, retains its separate identity and receive separate funding. Under Federal law, not all interstates are created equal.