Buses, ferries, trains, and planes are all regulated by the United States Department of Transportation if they are used to transport people or cargo across state lines. The federal government gets the power to regulate these types of transportation through the Commerce Clause of the Constitution, and specifically the Interstate Commerce Act. Buses, ferries, trains, and planes that do not cross state lines are regulated by the states in which they are registered and operate. The states have the authority to regulate any carriers that remain within their borders because the Constitution has delegated all power to the state's that are not expressly reserved for the federal government.
Understanding the FAA, Flight Regulations, and More
To better understand how regulation of transportation systems works, it is helpful to look at a specific example. One good example of how this works is the light rail passenger trains that travel through the state of Maryland. They are registered and regulated by the Maryland Transit Authority, or MTA. But a train that travels from Maryland to other areas of the country, such as a Norfolk Southern express train that is traveling to Pennsylvania, is registered and regulated by the federal government because it will cross state lines on its trip (as per the Commerce Clause). The same applies, of course, to airplanes and flight regulations, which are applied by the Federal Aviation Administration (FAA).
Because both the federal and state government have authority in different situations, if an accident takes place, there is always a governing body available to investigate the accident, and there is also regulation that will help to determine what laws, if any, have been broken.
Getting Help with Flight Regulations and Other Transportation Law Issues
If you have been involved in an accident with a bus, ferry, train, plane or any other "common carrier" that provides transportation to the public, you should consult with a lawyer for assistance in understanding what laws will govern your claim.