This final rule amends FHWA and FTA regulations implementing the National Environmental Policy Act (NEPA) and Section 4(f) requirements. In addition, through this final rule, FRA is joining those regulations, making them FRA's NEPA and Section 4(f) implementing regulations. The FHWA, FRA and FTA (hereafter collectively referred to as ``the Agencies'') modified the NEPA and Section 4(f) regulations to reflect various provisions of the Moving Ahead for Progress in the 21st Century Act (MAP-21) and the Fixing America's Surface Transportation (FAST) Act. The Agencies have also revised the Environmental Impact and Related Procedures regulations to reflect various procedural changes, such as including a new section on combined final environmental impact statement/record of decision documents, and to improve readability and reflect current practice. This final rule also amends the Parks, Recreation Areas, Wildlife and Waterfowl Refuges, and Historic Sites regulations to reflect new exceptions created by the FAST Act.