The Surface Transportation Board (STB) is an independent agency of the United States government that regulates interstate commerce in the areas of rail, trucking, and water transportation.

The Motor Carrier Act of 1980 is the primary federal law governing the safety of motor carriers. It sets forth regulations for the operation of commercial motor vehicles, including requirements for driver qualifications, vehicle maintenance, and hours of service.

Common carriers are held strictly liable for the loss or damage of goods entrusted to them, regardless of whether they were negligent. This means that they are liable even if they took all reasonable precautions to prevent the loss or damage.

The maximum weight limit for a single-axle vehicle operating on the interstate highway system is 20,000 pounds.

The maximum length limit for a commercial motor vehicle operating on the interstate highway system is 65 feet.

The maximum width limit for a commercial motor vehicle operating on the interstate highway system is 8 feet 6 inches.

The maximum height limit for a commercial motor vehicle operating on the interstate highway system is 13 feet 6 inches.

The maximum speed limit for a commercial motor vehicle operating on the interstate highway system is 65 mph.

The minimum age requirement for a driver of a commercial motor vehicle is 21 years old.

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

The minimum number of hours that a commercial motor vehicle driver must take off duty after operating a vehicle for 11 hours is 10 hours.

The maximum number of consecutive days that a commercial motor vehicle driver can operate a vehicle is 7 days.

The minimum number of hours that a commercial motor vehicle driver must take off duty after operating a vehicle for 7 consecutive days is 36 hours.

The maximum number of passengers that a school bus can carry is 70.

The minimum age requirement for a driver of a school bus is 21 years old.