WASHINGTON D.C. Motorcoach passengers using lap and shoulder restraints are likely to fair better in a head-on collision than those who are either unrestrained or using only lap belts, preliminary results of a government crash test indicate.

The test, performed in December for the National Highway Traffic Safety Administration, revealed that while crash dummies equipped with three-point restraints showed signs of some low head-and-neck impact, the other test dummies on the bus recorded much higher impacts to the head and other parts of their bodies.

"The results are not surprising," noted Ron Medford, the agency's senior associate for vehicle safety. "We've known for some time that the best protection is from three-point restraints."

He said other crash tests with automobiles and school buses have produced similar results.

The December crash test was the first ever done by the federal government using a motorcoach and the first of several the agency plans to conduct to study passenger restraints, roof strength, window glazing, and fires on full-size motorcoaches.

Industry onboard

The motorcoach industry has advocated for years that the federal government conduct crash and other tests with coaches before proposing any type of safety mandates for new coaches such as passenger restraints and structural modifications.

Engineers working at a facility in Ohio used a 45-foot, 54-seat 2000 MCI E-model motorcoach loaded with 22 dummies for the test, which involved crashing head-on into a barrier at 30 miles an hour.

The dummies used in the test were designed and weighted to represent both male and female passengers and were placed in various locations throughout the bus. Some were equipped with three-point restraints while others wore only lap belts or were unrestrained. All of them were wired to electronic testing equipment so researchers could evaluate their movements during the crash and the location and extent of any impact to their bodies.

According to early test readings, unbelted dummies typically made head contact with the seatback in front of them in less than a second and either ended up in the row in front of them or in the aisle. Some of the seats in front of unbelted dummies broke or bent from the impact of the dummies seated behind them.

While all of the belted dummies remained in their seats, those wearing lap belts still recorded high head impacts and those using combined lap and shoulder harnesses scored lower head loads. All of the dummies registered signs of some chest and leg loads from striking the seatback in front of them.

The seat attachments on the coach remained intact in the crash, although there were two notable failures one on a seat frame that was not designed for safety belts and another on a single ring connected to a safety belt.

'Not realistic'

Several motorcoach manufacturers and industry organizations, including the United Motorcoach Association, expressed concern about the manner in which the test was conducted. They said that crashing the full body height and width of the bus into a rigid barrier at 30 miles an hour was not realistic and suggested that the test would be more life-like if the speed of the coach were held to 20 miles an hour.

"This approach does not replicate the realistic scenarios faced by motorcoach operations," they said in a joint letter to the NHTSA. "As the agency is aware, European testing of larger motorcoaches is conducted with a 20 MPH crash speed, a speed which we believe better reflects real-world experiences."

Medford said engineers opted for the 30-mile-an-hour test because it is easier to scale down the speed on sled tests that will be conducted to simulate similar accidents at lower speeds. "With the data we obtained from the actual test, we will be able to simulate a crash at 20 miles an hour," he stressed.

While the test results are preliminary, Medford said the final results due out later are not expected to show anything different. They will, however, provide much more detail and include the actual video of the crash test.

The report, complete with pictures of the crash bus and the dummies, can be viewed on the Internet at www.regulations.gov. Under the heading More Search Options on the right side of the screen, click on Advanced Docket Searches. Put National Highway Traffic Safety Administration in the Agency box and NHTSA-2007-28793 in the Docked ID box. Then, click on Submit and when the next page appears, click on the highlighted docket number.

Meantime, the NHTSA is preparing for additional motorcoach tests, including roof crush and rollover tests that are scheduled for late this month at a facility in Wisconsin.

The agency plans to use four early 1990s MCI and Prevost coaches for those tests. All four buses will be modified to give engineers additional data for research and comparison purposes.

Medford said the agency also is working with the National Institute for Standards and Technology to finalize some fire tests that will be done soon.