Transportation, Housing and Urban Development, and Related Agencies Appropriations Act, 2018 Provides FY2018 appropriations to the Department of Transportation (DOT), the Department of Housing and Urban Development (HUD), and several related agencies. Department of Transportation Appropriations Act, 2018 Provides appropriations to DOT for: the Office of the Secretary, the Federal Aviation Administration, the Federal Highway Administration, the Federal Motor Carrier Safety Administration, the National Highway Traffic Safety Administration, the Federal Railroad Administration, the Federal Transit Administration, the Saint Lawrence Seaway Development Corporation, the Maritime Administration, the Pipeline and Hazardous Materials Safety Administration, and the Office of Inspector General. Department of Housing and Urban Development Appropriations Act, 2018 Provides appropriations to HUD for: Management and Administration, Program Office Salaries and Expenses, Public and Indian Housing, Community Planning and Development, Housing Programs, the Federal Housing Administration, the Government National Mortgage Association (Ginnie Mae), Policy Development and Research, Fair Housing and Equal Opportunity, the Office of Lead Hazard Control and Healthy Homes, the Information Technology Fund, and the Office of Inspector General. Provides appropriations to related agencies, including: the Access Board, the Federal Maritime Commission, the National Railroad Passenger Corporation (Amtrak) Office of Inspector General, the National Transportation Safety Board, the Neighborhood Reinvestment Corporation, the Surface Transportation Board, and the U.S. Interagency Council on Homelessness. Rescinds specified unobligated balances from prior appropriations. Sets forth permissible and prohibited uses for funds provided by this and other appropriations Acts.