The Department of Transportation

The FAA controls all civilian air traffic in U.S. airspace, handling roughly 45,000 flights a day, making it the busiest air traffic control system in the world, and certifies every commercial aircraft, pilot, and airline operating in the United States as meeting federal safety standards.

The FAA has faced sustained scrutiny in recent years over air traffic controller staffing shortages and aging air traffic control technology, issues that drew renewed national attention following a series of high-profile aviation safety incidents and near-misses at major U.S. airports.

The agency employs roughly 45,000 people, including about 14,000 certified air traffic controllers at more than 300 facilities, and is chronically several thousand controllers short of its own staffing targets. Much of its equipment is decades old; a 1988-era system that alerts pilots to hazards failed for hours in January 2023, briefly halting all U.S. departures for the first time since 9/11.

The FAA also runs the aviation trust fund financed by ticket and fuel taxes, regulates commercial spaceflight launches, and writes the rules for drones, which now number well over a million registered aircraft. Unlike most safety regulators it has a legal "dual mandate" that once included promoting the aviation industry, a phrase Congress removed in 1996 after the ValuJet crash.

NHTSA sets federal motor vehicle safety standards, investigates vehicle defects, and can order manufacturers to recall unsafe vehicles or parts, with tens of millions of vehicles recalled for safety defects in a typical year, ranging from faulty airbags to software glitches.

The agency also runs highway safety campaigns like 'Click It or Buckle Up' and collects the national traffic fatality statistics that guide both federal policy and vehicle safety technology requirements, including the eventual mandate for rearview cameras and, more recently, automatic emergency braking systems.

Roughly 40,000 people die on U.S. roads each year, a rate far higher per mile driven than in most other wealthy countries, and NHTSA's statistics show pedestrian and cyclist deaths rising sharply in the 2010s and 2020s even as vehicle occupant deaths fell.

NHTSA also administers the federal fuel-economy (CAFE) standards jointly with the EPA, oversees the 5-Star crash-test rating program consumers see on window stickers, and writes the still-evolving federal framework for automated and self-driving vehicles, an area where it has mostly used exemptions and guidance rather than binding rules.

The Federal Highway Administration distributes federal highway funding to state departments of transportation, primarily financed through the federal gas tax deposited into the Highway Trust Fund, supporting construction and maintenance of the roughly 47,000-mile Interstate Highway System and other federally supported roads.

Because the federal gas tax has not been raised since 1993 while construction costs and vehicle fuel efficiency have both risen substantially, the Highway Trust Fund has required repeated general fund transfers from Congress in recent years to remain solvent, an ongoing structural funding challenge for the agency.

About 90 percent of the agency's budget flows to states as formula grants, and states generally must put up a 20 percent match. The FHWA sets national design and signage standards (the Manual on Uniform Traffic Control Devices is why a stop sign looks the same in every state) and reviews the environmental studies required for large projects.

The federal government owns almost none of the roads it funds; states and localities own and maintain them. The FHWA does directly manage about 30,000 miles of roads on federal land, such as those in national parks and forests, through its Federal Lands Highway program.

The Federal Railroad Administration regulates railroad safety nationwide and provides federal funding and oversight for Amtrak, the government-supported national passenger rail system, along with major rail infrastructure investments like the Northeast Corridor upgrades between Boston and Washington, D.C.

The agency also oversees freight rail safety regulations affecting the extensive private freight rail network that moves the majority of the nation's coal, grain, and other bulk commodities, and its safety investigations have drawn significant attention following high-profile derailments involving hazardous materials.

The FRA has only a few hundred inspectors for roughly 140,000 miles of track, so it relies heavily on railroad self-reporting and audits. It administered the long, contentious rollout of "positive train control," an automatic braking system Congress mandated after a 2008 California collision killed 25; it finally covered the required network in 2020.

The February 2023 Norfolk Southern derailment and chemical burn-off in East Palestine, Ohio, put the agency's freight-safety rules in the spotlight and prompted bipartisan rail-safety bills in Congress over train length, crew size, and trackside detectors.

Though authorized under the 1956 Federal-Aid Highway Act, before the Transportation Department itself existed, the roughly 47,000-mile Interstate Highway System took decades to complete, with the Federal Highway Administration overseeing its final major segments into the 1990s.

The interstate system is widely regarded as one of the most transformative public works projects in American history, reshaping commerce, suburban development, and personal mobility nationwide, and it remains the backbone of the department's highway funding and maintenance responsibilities today.

The 1956 law paid 90 percent of construction costs from a new federal gas tax and Highway Trust Fund, and President Eisenhower promoted it partly on Cold War grounds, as a way to move troops and evacuate cities. Final cost estimates ran to well over $100 billion (far more in today's dollars), and the last originally planned segment opened in 1992 in Colorado.

The routing of urban interstates through the hearts of cities in the 1950s and 1960s displaced hundreds of thousands of people, disproportionately in Black neighborhoods, and "freeway revolts" halted planned highways in San Francisco, New York, and other cities. The 2021 law added a program to help reconnect neighborhoods that earlier highways divided.

When most of the FAA's unionized air traffic controllers went on an illegal strike in August 1981, President Reagan fired more than 11,000 striking controllers and banned them from federal service, a decision that reshaped labor relations across the federal government for decades.

The FAA spent years rebuilding its controller workforce afterward, and staffing shortages tracing partly back to this disruption have periodically resurfaced as a persistent operational challenge for the agency, contributing to more recent concerns about controller staffing levels.

Federal law bars federal employees from striking, and the union, PATCO, was decertified. Reagan's willingness to fire the entire workforce is widely cited by labor historians as a turning point that emboldened private employers to take harder lines in strikes through the 1980s.

Because the FAA hired a huge cohort of replacement controllers in the early 1980s, they later became eligible to retire in a bunch around 2010-2015, creating a second staffing crunch, and controllers face mandatory retirement at 56, which keeps the pipeline problem recurring.

Two crashes of Boeing 737 MAX aircraft in 2018 and 2019, which killed 346 people combined, revealed serious flaws in how the FAA had delegated aspects of aircraft safety certification to Boeing itself, prompting a worldwide grounding of the aircraft and a major congressional overhaul of FAA certification oversight in 2020.

The crisis significantly damaged public confidence in the FAA's certification process and led to new legal requirements strengthening the agency's direct oversight role, changes still being implemented as the FAA works to restore its safety oversight credibility.

Both crashes were tied to a flight-control system called MCAS that could push the plane's nose down based on a single sensor, and that pilots had not been told about. The MAX was grounded worldwide for about 20 months, the longest grounding of a U.S. airliner ever.

The Aircraft Certification, Safety, and Accountability Act of 2020 tightened rules on "organization designation authorization," the system that lets manufacturers self-certify routine work. Boeing paid a $2.5 billion settlement, and further quality problems, including a door plug that blew out of a 737 MAX 9 in flight in January 2024, kept the FAA's oversight of the company under scrutiny.

Financed primarily by the federal gas and diesel tax, unchanged since 1993, the Highway Trust Fund provides the majority of federal highway and transit funding distributed to states, though rising construction costs and improved vehicle fuel efficiency have steadily eroded its purchasing power over time.

Congress has repeatedly transferred general revenue into the trust fund to keep it solvent in recent years, and the long-term question of how to fund highways as vehicles become more fuel-efficient and electric, reducing gas tax revenue, remains one of the department's most significant unresolved policy challenges.

The federal gas tax is 18.4 cents a gallon (24.4 for diesel) and has lost roughly half its real value since 1993. Since 2008 Congress has plugged more than $270 billion in general-fund and other transfers into the trust fund because gas-tax revenue no longer covers the spending Congress authorizes.

Several states are piloting a "road usage charge" that taxes miles driven rather than fuel bought, and the 2021 law funded a national pilot. Electric-vehicle drivers currently pay no federal fuel tax at all, and many states have added flat EV registration fees to compensate.

NHTSA can compel automakers to recall vehicles with safety defects, and tens of millions of vehicles are recalled in a typical year for issues ranging from faulty airbag inflators to software errors, with owners notified directly and repairs performed free of charge by dealers.

The 2014-era Takata airbag recall, which eventually covered tens of millions of vehicles across nearly every major automaker due to airbag inflators that could explode with metal shrapnel, remains the largest automotive safety recall in U.S. history and reshaped how NHTSA investigates supplier-wide safety defects.

The Takata recall covered about 67 million inflators in the U.S. and is linked to more than 25 U.S. deaths; the company filed for bankruptcy in 2017. Because completion rates on recalls are far from 100 percent, millions of affected vehicles remained on the road years later, and NHTSA and automakers still run campaigns to reach the last owners.

Most recalls begin voluntarily after a manufacturer's own analysis or NHTSA's Office of Defects Investigation opens a query based on consumer complaints. NHTSA can also fine automakers for failing to report defects promptly, as it did in multibillion-dollar-adjacent penalties against several companies over ignition switches, unintended acceleration, and delayed reporting.

Funded by the 2021 infrastructure law, this program provides states with federal funding to build a nationwide network of fast-charging stations along major highway corridors, aimed at addressing 'range anxiety' concerns that have historically slowed broader electric vehicle adoption, particularly for long-distance travel.

Implementation has moved more slowly than initially planned, with states navigating complex federal requirements and private charging network partnerships, and the program's future scope has become a subject of ongoing policy debate as electric vehicle adoption rates and federal priorities have shifted.

The program's $5 billion is distributed to states by formula and aims for chargers at least every 50 miles along designated highway corridors, each site with at least four fast-charging ports. Standards require the chargers to work with any brand of car and to meet uptime and payment rules.

By the mid-2020s only a few hundred federally funded charging ports had opened, drawing bipartisan criticism over the pace, and a 2025 administration move to pause the program while rewriting the rules was challenged by several states in court.

The Federal Transit Administration provides grants to help cities build and maintain subway systems, bus networks, and light rail, funding major capital projects through its Capital Investment Grants program, which typically covers up to half the cost of large new transit projects nationwide.

Transit funding has become an increasingly significant part of the department's portfolio as cities look to reduce traffic congestion and emissions, though major transit expansion projects in the U.S. frequently face longer timelines and higher per-mile costs than comparable projects in many other developed countries.

About 80 percent of federal transit dollars go to formula grants that agencies use mostly for maintenance and equipment; the competitive "New Starts" pipeline funds a smaller number of big projects and often takes a decade from application to opening. The FTA also tracks a large "state of good repair" backlog, tens of billions of dollars of overdue rail and bus repairs.

Fare revenue covers only part of transit operating costs, and ridership on many U.S. systems, especially rail, fell sharply during the pandemic and had not fully recovered by the mid-2020s, leaving agencies facing "fiscal cliffs" as federal relief funds ran out.