State and local governments conduct metropolitan and statewide planning to develop coordinated, financially constrained system plans to meet transportation needs for local and statewide systems, under FHWA's planning regulations contained in 23 CFR part 450. In addition, air quality non-attainment areas must meet the requirements of the U.S. EPA Transportation conformity regulations (40 CFR parts 51 and 93). Projects must be included in an approved State Transportation Improvement Program (STIP) in order to be eligible for Federal-aid funding.