Transportation covers all the major federal modes — highways, aviation, transit, rail, maritime — and totals about $137 billion in FY2024. The biggest single piece is the Federal-Aid Highway Program (~$50B), which distributes Highway Trust Fund dollars to state DOTs by formula. The states then award the actual construction contracts.
Other major pieces: the Federal Aviation Administration (~$20B) runs air traffic control and aviation safety; the Federal Transit Administration (~$20B) sends grants to local transit agencies (MTA in NYC, LA Metro, WMATA in DC, CTA in Chicago, MBTA in Boston); the Coast Guard (~$14B) handles maritime law enforcement and search & rescue; and the Federal Railroad Administration (~$8B) subsidizes Amtrak operations and corridor improvements.
On the federal contractor side, Raytheon/RTX is the FAA's biggest tech vendor (radar, NextGen automation), Leidos and Lockheed Martin do FAA and Coast Guard IT, Bollinger Shipyards builds Coast Guard cutters, and engineering firms like HNTB, AECOM, and Jacobs do federally-funded design work on highway, transit, and rail projects nationwide.