In Brown v. Board of Education, the Supreme Court held that racial segregation of children in public schools was unconstitutional. This decision had a profound impact on transportation law, as it led to the desegregation of school buses and other forms of transportation used to transport students.

The FAA is the federal agency responsible for regulating air traffic, ensuring the safety of civil aviation, investigating aircraft accidents and incidents, and certifying aircraft and pilots.

The ADA is a civil rights law that prohibits discrimination against individuals with disabilities. It requires public transportation systems, employers, and businesses and public places to be accessible to individuals with disabilities.

In Roe v. Wade, the Supreme Court held that the right to privacy includes the right to have an abortion. This decision has had a significant impact on transportation law, as it has led to challenges to laws that restrict access to abortion services.

The NHTSA is the federal agency responsible for setting and enforcing safety standards for motor vehicles, investigating motor vehicle accidents, and recalling defective vehicles.

The FMCSA is the federal agency responsible for regulating the safety of commercial motor vehicles, enforcing hours-of-service regulations for truck drivers, and inspecting commercial motor vehicles.

The STB is the federal agency responsible for regulating the economic aspects of rail, truck, and water transportation, resolving disputes between shippers and carriers, and approving mergers and acquisitions in the transportation industry.

In Citizens United v. Federal Election Commission, the Supreme Court held that corporations have the same First Amendment rights as individuals, including the right to spend money on political campaigns. This decision has had a significant impact on transportation law, as it has led to challenges to laws that restrict corporate spending on political campaigns.

The FRA is the federal agency responsible for regulating the safety of railroads, investigating railroad accidents, and certifying locomotives and railroad cars.

The PHMSA is the federal agency responsible for regulating the safety of pipelines and hazardous materials transportation, investigating pipeline and hazardous materials accidents, and enforcing safety regulations for pipelines and hazardous materials transportation.

In Shelby County v. Holder, the Supreme Court held that Section 4 of the Voting Rights Act, which required certain states to obtain preclearance from the federal government before changing their voting laws, was unconstitutional. This decision has had a significant impact on transportation law, as it has led to challenges to laws that restrict access to voting.

The NTSB is the federal agency responsible for investigating transportation accidents, determining the probable cause of transportation accidents, and making recommendations to prevent future transportation accidents.

The FTA is the federal agency responsible for providing financial assistance for public transportation projects, setting and enforcing safety standards for public transportation systems, and promoting the use of public transportation.

In District of Columbia v. Heller, the Supreme Court held that the Second Amendment protects an individual's right to keep and bear arms for traditionally lawful purposes, such as self-defense in the home. This decision has had a significant impact on transportation law, as it has led to challenges to laws that restrict the transportation of firearms.

The MARAD is the federal agency responsible for promoting the development of the U.S. merchant marine, providing financial assistance to the U.S. merchant marine, and regulating the safety of U.S. merchant vessels.