The United States Department of Transportation, National Highway Traffic Safety Administration (NHTSA), has been actively researching ways to improve bus safety for several years. In 2007, NHTSA completed a broad review of motorcoach safety issues in the United States and developed an approach that would be pursued to most expediently address those issues. This paper discusses the priority areas that are being investigated for improvements, presents the approach that is being taken in each priority area, and summarizes the status and research results obtained thus far.

While there are a number of agency programs that encompass motorcoaches, the agency has decided to pursue these efforts as priorities:​ passenger ejection, roof strength, fire safety, and emergency evacuation.

For passenger ejection, incorporation of seat belts has been pursued as the most expedient way to mitigate ejection. A full scale frontal 30 mph barrier crash test was conducted to measure the occupant responses for both belted and unbelted conditions, and sled testing under a variety of configurations was completed to assess seat anchorage and seat belt load experienced under these conditions.

Regarding roof strength, tests on four motorcoaches were conducted to assess and compare European and U.S. requirements for roof strength in buses. Survival space and emergency exit operation were studied for both test conditions.

To address emergency evacuation on motorcoaches, studies and human evacuation simulations are being conducted. Various emergency exit scenarios including windows, rear stairs/door, existing wheelchair exit doors, airplane style portals, and roof exits are being evaluated. Minimum strength requirements for opening emergency exits based on the age of the occupant are also being examined.

As for fire safety, NHTSA is conducting research to examine how a motorcoach fire spreads from the wheel well to and through the passenger compartment. The flammability of interior and exterior materials will be investigated, as well as detection systems to warn the driver of an external fire along with automatic suppression systems to quell a fire before it spreads.