NTSB Number: SS-89/02 NTIS Number: PB89-917003
Federal standards for the design and operation of school buses differ according to the passenger capacity and gross vehicle weight rating of the bus. The Safety Board, therefore, studied the performance of large and small school buses separately, and two reports were planned.
The first report, published in 1987, examined the crash performance of large school buses built after the new standards for school buses became effective. The Safety Board found, overall, that large poststandard school buses provided excellent crash protection to their passengers, but issued recommendations to further refine the safety of these school buses. The Safety Board concluded that the first priority for improving the safety of school bus passengers should be the rapid retirement of prestandard school buses, followed by expenditure of funds toward accident prevention in the form of improved driver training and equipment to reduce the number of student fatalities occurring during the loading and unloading of large school buses. Two to three times as many students are killed each year in the loading zones as are killed while riding on the school buses.
This is the second report on school bus safety; it focuses on the performance of small school buses and vans used for school transportation. The report is based on review of past research, crash tests, and the Safety Board's investigation of accidents involving vehicles used for school transportation manufactured after April 1, 1977. Safety Board highway investigators, working out of eight Regional Offices, established notification networks with State and local police, hospitals and emergency personnel, and safety groups, and asked to be alerted when a crash meeting the Safety Board's criteria occurred. To be investigated for the study, the crash had to meet at least one of the following criteria: damage to the school vehicle that required it be towed from the scene, the school vehicle rolled over, or one or more bus passengers was seriously injured or killed. Accidents in which these elements occur put passengers at risk of injury. As a result, the design of the bus, in terms of occupant protection, can be evaluated. The typical school bus accident, which results in property damage only and in which the bus is driven from the accident scene, does not "test" the crashworthiness of the vehicle.
The Safety Board found that occupants of the small school buses built to Federal school bus standards generally fared well in the accidents investigated. Injuries, when sustained, were generally minor and were primarily to the face, head, or lower limbs. Unrestrained and lapbelted passengers showed similar patterns of minor injuries, and seating position, more than restraint status, appeared to influence the severity of injuries. Passengers seated in the front rows of certain types of small school buses appeared to be at increased risk of head or facial injuries because of the absence or peculiar design of a restraining barrier. Lapbelted passengers, in particular, appeared to be at risk of injury from interaction with the restraining barriers.
Lapbelt use did not appear to hamper emergency evacuation of passengers, primarily because adults on the scene rapidly released the passengers from their belts. No postcrash fires or leaks from the school bus fuel tanks occurred. In many accidents, however, school bus passengers were limited in the number of emergency exits available: after the crash, exits were often blocked or inoperable.
Other issues addressed in this report include: inaccurate reporting
of restraint status and injuries; improper use and installation of lapbelts;
windshield dislodgement; inadvertent opening of the boarding door during
the crash; and separation of body Joints.
As a result of this safety study, recommendations were issued to the
National Highway Traffic Safety Administration, manufacturers of small
school buses and various associations of school transportation officials
and contractors. The recommendations focus on the following safety concerns:
--to the National Highway Traffic Safety Administration:
Determine the feasibility of requiring lap/shoulder belts or other restraint systems that provide upper torso restraint at front seat passenger seating positions on Type A school buses (gross vehicle weight rating of 10,000 pounds or less). Amend Federal Motor Vehicle Safety Standard (FMVSS) 222, "School Bus Passenger Seating and Crash Protection," and FMVSS 210, 'Seat Belt Assembly Anchorages,' or any other standards, as needed, should standards prove incompatible. (Class II, Priority Action) (H-89-46)
Conduct research, including computer simulation and sled crash tests using Hybrid III dummies if needed, to determine the relationship between restraining-barrier design and injuries to unrestrained and lapbelted passengers of different sizes on small school buses (gross vehicle weight rating of 10,000 pounds or less). Research should focus on the height, width, padding, location, and anchorage strength of the barrier, and the spacing between the barrier and front seats. Amend Federal Motor Vehicle Safety Standard 222, "School Bus Passenger Seating and Crash Protection," as needed. (Class II, Priority Action) (H-89-47)
Amend Federal Motor Vehicle Safety Standard 217, "Bus Window Retention and Release," to include a performance standard for the minimum retention of windshields in all sizes of school buses. (Class II, Priority Action) (H-89-48)
Collect and evaluate accident data on the crash performance of the roof and emergency exits on small school buses (gross vehicle weight rating of 10,000 pounds or less in rollovers. Data should not be limited to van-based buses. Based on analysis, ascertain whether it is appropriate to amend Federal Motor Vehicle Safety Standard 220, "School Bus Rollover Protection," to make roof performance tests for small school buses (gross vehicle weight of 10,000 pounds or less) to be identical in all aspects to those now required of large school buses (gross vehicle weight rating of more than 10,000 pounds). If such tests are not appropriate, modify the test for small school buses to stress the roof more than the present force application plate test does. (Class II, Priority Action) (H-89-49)
Collect and evaluate accident data involving small school buses to ascertain whether school buses with a gross vehicle weight rating of 10,000 pounds or less should be required to meet joint strength requirements of Federal Motor Vehicle Safety Standard 221, "School Bus Body Joint Strength." (Class II, Priority Action) (H-89-50)
Specify in new rulemaking or in an amendment to Federal Motor Vehicle Safety Standard 206, 'Door Locks and Door Retention Components," a requirement for a positive latch locking mechanism on the passenger loading doors of small school buses (gross vehicle weight rating of 10,000 pounds or less) to eliminate the possibility of inadvertent door opening during a frontal crash or rollover. Work with school bus and school van manufacturers to develop the performance standards. (Class II, Priority Action) (H-89-51)
Urge manufacturers to provide means to retrofit positive latch locking mechanisms on existing door controls of small school buses (gross vehicle weight rating- of 10,000 pounds or less). (Class II, Priority Action) (H-89-52)
--to members of the School Bus Manufacturers Institute and manufacturers of van conversion school buses:
Work with National Highway Traffic Safety Administration to develop performance standards for a locking mechanism for the boarding doors of school buses with a gross vehicle weight rating of 10,000 pounds or less to eliminate the possibility of inadvertent door opening during frontal or rollover crash. (Class II, Priority Action) (H-89-53)
Provide retrofit kits for small school buses (gross vehicle weight rating of 10,000 pounds or less) currently without positive latch door control locking mechanisms. (Class II, Priority Action) (H-89-54)
--to the National Association of State Directors of Pupil Transportation, the National Association of Pupil Transportation, and the National School Transportation Association:
Alert your members to the dangers inherent in improper installation of seatbelts and/or installation of restraint systems not meeting Federal standards or guidelines in school buses and urge them to correct such installations. Also alert your members of the need to instruct students to wear lapbelts properly. (Class II, Priority Action) (H-89-55)