WASHINGTON -- A commercial driver delivering an empty passenger-carrying motor vehicle, such as a bus, must abide by property-carrier hours-of-service rules, according to a federal rule clarification.

In other words, the bus driver must abide by the hours-of-service rules that apply to truck drivers.

The Federal Motor Carrier Safety Administration provided the new guidance because the terms "property-carrying" and "passenger-carrying" are not defined in its hours-of-service rules.

The new rules went into effect last month.

Property-carrier hours-of-service rules apply when an empty commercial passenger-carrying vehicle "with one or more sets of wheels on the surface of the roadway" is being transported:

(1) Between the vehicle manufacturers facilities

(2) Between a vehicle manufacturer and a dealership or purchaser

(3) Between a dealership or other entity selling or leasing the vehicle and a purchaser or lessee

(4) To a motor carrier's terminal or repair facility for the repair of disabling damage following a crash

(5) To a motor carrier's terminal or repair facility for repairs associated with the failure of a vehicle component or system

(6) By means of a saddle-mount or tow-bar, according to the clarification.

Heres how the new rules apply in various real-world scenarios, according to the FMCSA:

Q. What happens if a driver operates both a bus and truck for part of each day or each week?

A. A driver will be subject to the limits on driving time applicable to the commercial motor vehicle the driver is driving (11 hours for a property-carrying commercial motor vehicle, 10 hours for a passenger commercial motor vehicle), and will be required to meet the off-duty requirements applicable to the type of commercial motor vehicle the driver will drive immediately after that off-duty period (10 hours if the next assignment is in a property-carrying vehicle, 8 hours if it is in a passenger vehicle).

For example, if a bus driver completes 8 hours off-duty for the motorcoach company, the driver must remain off-duty for another 2 hours before driving for the trucking company.

After completing 10 consecutive hours off-duty, the driver may drive for 11 hours for the trucking company. Following 8 consecutive hours off-duty, the driver may then drive for the bus company.

Q. What if a driver who is employed by a bus company, rather than the dealer or manufacturer, delivers the vehicle from the manufacturers facilities to the bus company? Is the driver under passenger-carrying or property-carrying rules?

A. The bus is being delivered for the first time from the dealer/manufacturer to the end-user, in which case the property-carrying rules would be applicable.

Q. What if the bus company driver who is delivering the bus brings along a mechanic to inspect the vehicle before delivery, and the mechanic is now getting a ride home?

A. This single rider is an employee of or contractor for the company, and would not change the nature of the transportation any more than a mechanic riding in a truck-tractor cab. It would still be a property-carrying scenario for this first trip to the end-users facilities.

Q. What happens in the case of a breakdown? For example, if the air conditioner on a bus with passengers breaks down, the passengers are put on another bus, and the bus with the broken air-conditioner is driven back by its driver. Is the driver under passenger-carrying or property-carrying rules?

A. This would be a "driveaway-towaway operation," as defined in the new rules, and would be covered under property-carrying rules, just as if a mechanic or relief driver were sent out to bring the bus in.