Updated

WASHINGTON -- Federal transportation officials are proposing that motorcoach operators be required to install seatbelts in their buses for the first time.

Under a regulation proposed by the U.S. Department of Transportation on Monday, operators would have three years to install lap-shoulder belts.

Seatbelts can reduce deaths in motorcoach rollover accidents by an estimated 77 percent. The lack of seatbelts has been cited by investigators as a factor in several fatal accidents.

Nine people were killed and 43 injured in a January 2008 crash near Mexican Hat, Utah. The bus' roof was sheared off and everyone aboard ejected except for the driver, who was wearing the only seatbelt on the bus, and one man who was pinned between two seats.