The Pipeline and Hazardous Materials Safety Administration (PHMSA) is responsible for regulating the transportation of hazardous materials by all modes of transportation, including pipelines, highways, railroads, and waterways.

The FMCSA is responsible for regulating the safety of commercial motor vehicles, including trucks, buses, and other vehicles used to transport goods or passengers.

The Motor Carrier Safety Act of 1984 establishes minimum safety standards for motor carriers engaged in interstate commerce, including requirements for driver qualifications, vehicle maintenance, and hours of service.

The maximum number of hours a commercial motor vehicle driver can operate a vehicle in a 24-hour period is 11 hours.

The Federal Aviation Administration (FAA) is responsible for regulating the transportation of passengers by air, including the safety of aircraft, airports, and air traffic control.

The FRA is responsible for regulating the safety of railroads, including track maintenance, locomotive inspections, and train operations.

The Railroad Safety Act of 1970 establishes minimum safety standards for railroads engaged in interstate commerce, including requirements for track maintenance, locomotive inspections, and train operations.

The maximum speed limit for a passenger train in a densely populated area is 30 mph.

The FMC is responsible for regulating the transportation of passengers by water, including the safety of passenger vessels, ports, and terminals.

The NHTSA is responsible for regulating the safety of motor vehicles and highways, including the development of safety standards for vehicles, tires, and equipment.

The National Traffic and Motor Vehicle Safety Act of 1966 establishes minimum safety standards for motor vehicles sold in the United States, including requirements for seat belts, airbags, and crashworthiness.

The maximum speed limit for a school bus in a school zone is 15 mph.

The PHMSA is responsible for regulating the transportation of oil and gas by pipeline, including the safety of pipelines, pumping stations, and terminals.

The STB is responsible for regulating the economic aspects of transportation by rail, truck, and water, including rates, fares, and service levels.

The Pipeline Safety Act of 1979 establishes minimum safety standards for pipelines transporting hazardous materials, including requirements for pipeline design, construction, and operation.