Sets national transportation safety rules across air, road, rail, and pipeline — but doesn’t build most of the roads it regulates.
DOT covers aviation safety, highway and transit funding, rail and pipeline safety, and vehicle safety standards. Most people encounter it through the FAA at an airport or NHTSA’s vehicle recall and crash-test data, without realizing both sit under the same department.
DOT’s mission is to deliver the world’s leading transportation system, serving the American people and economy through the safe, efficient, sustainable, and equitable movement of people and goods.
Department of Transportation mission statement
What It Does
DOT was created in 1966 to consolidate federal transportation functions that had been scattered across multiple agencies. It sets safety standards and provides infrastructure funding across nearly every mode of transportation, but actual road construction and most transit operation happen at the state and local level using DOT funding and rules.
Regulates aviation
The FAA certifies aircraft, licenses pilots, and manages the national airspace system.
Funds highways
The Federal Highway Administration distributes federal funding to states for road construction and maintenance.
Sets vehicle safety standards
NHTSA sets vehicle safety standards, investigates defects, and manages vehicle recalls.
Oversees rail and pipeline safety
The Federal Railroad Administration and PHMSA regulate rail and pipeline safety nationwide.
How It Fits Into Government
A funder and regulator, not a builder
DOT sets safety standards and distributes federal funding across transportation modes, but state departments of transportation and local transit agencies actually build roads and run most transit systems using that funding. Congress writes the surface transportation authorization bill roughly every five years, setting the statutory framework for most highway and transit funding, and appropriates DOT’s annual budget.
Major Agencies
FAA
Aviation safety, air traffic control, and pilot certification.
- Air traffic control
- Aircraft certification
- Pilot licensing
Federal Highway Administration
Distributes federal highway funding to states.
- Highway grants
- Bridge funding
NHTSA
Vehicle safety standards, crash testing, and recalls.
- Safety standards
- Recall investigations
- Crash data
How It Is Checked
Congress
Passes surface transportation authorization roughly every five years and funds DOT’s annual budget.
Courts
Review DOT rulemaking and can set aside safety standards exceeding statutory authority.
Public process
Vehicle safety and aviation rules generally go through notice-and-comment before final adoption.
Inspector General
The DOT OIG audits programs and investigates fraud in infrastructure grants and safety programs.
Public Services Visitors May Need
Check air travel rightsFlight delay, cancellation, and disability accommodation rules.→
Look up pipeline or rail safety dataPHMSA and FRA incident and inspection records.→
Find infrastructure grant programsHighway, transit, and airport funding opportunities.→
DOT doesn’t build the roads it funds
A common misconception is that federal highways are built and maintained directly by DOT. In practice, DOT sets standards and distributes funding through formula and grant programs, but state departments of transportation actually design, build, and maintain the roads — even ones bearing an interstate designation. A pothole complaint almost always belongs with a state or local transportation department, not DOT in Washington.
