The purpose of this subpart is to implement the requirements of 23 U.S.C. 150(c)(3)(A)(ii)(III) , which requires the Secretary of Transportation to establish performance measures for the purpose of carrying out the NHPP and for State DOTs and MPOs to use in assessing the condition of bridges carrying the NHS which includes on- and off-ramps connected to the NHS.
23 C.F.R. § 490.401