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Collision
of Small School
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| Webmaster Note: This comment about lapbelts in small school buses is taken from the National Transportation Safety Board's Highway Accident Investigation of the Snyder, Okla. school bus accident. The accident occured on Nov. 10, 1993. Fatalities occured to four children. Only sections pertinent to the Great Seat Belt Debate are presented here. Contact the NTSB at 202/382-6847 to obtain a complete copy of the report. Or click here to visit the NTSB website.The report can be obtained from the National Technical Information Service. Ask for PB94-916204. |
EXECUTIVE SUMMARY p. v
About 3:28 p.m. on November
10, 1993, near Snyder, Oklahoma, a tractor-semi-trailer traveling southbound
on U.S. Route 183 struck a 1993 Thomas Built Minotour school bus that was
crossing the highway while traveling west on County Line Road. The 20-passenger
school bus was occupied by the driver and nine children. The school bus driver
said that she stopped at the stop sign and then proceeded to drive across
Route 183. The truck driver stated that the school bus driver hesitated and
then pulled out in front of his truck. The school bus was struck in the right
side behind the right-front entrance door. Eight children were not wearing
the available lapbelts and were ejected. Four of the ejected children died;
the injuries of the other four ranged from minor to serious. One child, the
only occupant of the bus who was restrained was not ejected; he received minor
injuries. The school bus driver was not ejected, but she was not wearing the
lap-shoulder restraint and sustained severe injuries from contact with various
parts of the bus interior. The truck driver, who stated that he was wearing
his lapbelt, received minor injuries.
The National Transportation Safety Board determines
that the probable cause of the accident was that the school bus driver did
not see the approaching truck because her view was obstructed, because she
had not been provided with an effective strategy or other means for overcoming
the view obstruction, and because she may have been distracted by the unruly
passengers. Contributing to the severity of the accident were the truck driver's
failure to observe the speed advisory and the Cornell Construction Company's
failure to systematically maintain the accident truck.
The safety issues identified in this accident are
the protection provided school bus occupants, the performance of the school
bus driver and the view obstruction in the bus, the performance of the truck
driver, and the adequacy of motor carrier oversight.
As a result of the investigation of this accident,
the Safety Board makes recommendations to the National Highway Traffic Safety
Administration, the Federal Highway Administration, the Governors of the 50
States and the mayor of the District of Columbia, the National Association
of State Directors of Pupil Transportation Service, and the Cornell Construction
Company.
(Webmaster's note: pps. 1-30 detailing the NTSB's accident investigation have been omitted.)
Protection Provided School Bus Occupants (pps.30 -- 35)
Lapbelt use -- Safety Board investigators visually examined the lapbelts before removing them from the bus on November 19, 1993. In February 1994, the Safety Board further analyzed the lapbelts, including the driver's lap-shoulder restraint, using standard lapbelt analysis techniques (19) -- materials science, fiber analysis, and studies of the witness marks resulting from the mechanical effects of lapbelts in accidents. The Board examined the lapbelts with the Nikon Stereozoom microscope, removed selected samples of foreign matter, and subjected the samples to x-ray energy spectroscopy.
The lapbelts taken from seat 1D showed positive indicators that confirmed its use during the accident; it clearly showed imprints and crushed fibers in the belt webbing, as well as latchplate and cinchplate imprinting. This belt, which was cut by the passerby to free the 5-year-old boy (passenger #2) in seat 1D, was used as a control during the testing. No other lapbelts showed evidence of use during the accident. Therefore, the Safety Board concludes that the eight children who were ejected were not wearing their lapbelts.
The school bus driver stated that she was wearing her lap-shoulder restraint loosely and that her hand struck the restraint's release mechanism during the accident. However, the restraint had no positive witness markings. Just before the collision, the school busdriver had turned around in her seat to scold the students, and she may have released her lap-shoulder restraint in order to do so. In addition, the student seated directly behind her said that she was not wearing the restraint. Based on this evidence and on the fact that she was ejected from her seat, the Safefty Board concludes that the school bus driver was not wearing her lap-shoulder restraint when the accident occurred.
Outcome for the Occupants -- The school busdriver's head struck the windshield, and her body hit the dashboard and the door-opening mechanism. These impacts probably caused her fractured right ribs and internal injuries. The school bus driver was then thrown to the bottom of the stepwell area. If she had been restrained by the available lap-shoulder belt, she would not have been thrown out of her seat and her injuries probably would have been less severe.
Passenger 1 believes that he was ejected through the right-front entrance door. If so, his injuries were probably caused by contact with the door or interior bus components near the door. His injuries were minor, and after the accident, he was able to move around and assist other passengers until help arrived. This student was not in the impact area (figure 10). If he had been restrained, he would not have been ejected and might have sustained injuries similar to those of passenger 2.
Passenger 2, who also sustained minor injuries, was restrained by his lapbelt throughout the accident sequence. The lapbelt inflicted a bruise over his pelvic bone. His concussion may have been caused by contact with passenger 3 or by the dislodged seat cushion found on top of him. If he had not been restrained, he probably would have been ejected.
Passengers 3,4,7, and 8 were all found within 40 feet of the bus. These students sustained internal injuries, head injuries, ad multiple fractures. Such injuries could have resulted from striking each other, the truck, the right inside sidewall and roof of the bus, components of the right-side windows, or the ground. Passenger 3, whose injuries were severe, was on the perimeter of the impact area. If he had been restrained, he would not have been ejected. He might have been injured by the lapbelt or by contact with passenger 2 or the right sidewall, but those injuries would probably have been less severe. Passenger 4 sustained serious injuries on her left side. If she had been restrained, she would not have been ejected. However, she was sitting on a three-passenger bench seat, and her exact position when the impact occurred is unknown. If she had been restrained in the window seat, she would have been in the impact area and could have been killed. Passnger 7, who died at the scene, was seated in the impact area near the window. Although a lapbelt would have prevented his ejection, it would probably not have prevented his fatal injuries. The truck intruded into the bus where he was sitting. Passenger 8, who died the following day from an undefined head wound, was not in the impact area. If she had been restrained, she would not have been ejected, and her chances for survival might have been better.
Passengers 5,6, and 9 were probably dragged or run over by the bus. They were found about 5 feet from the right side of the bus. Unlike the other ejected occupants, these three passengers had massive external injuries; their bodies were covered with dirt, and dirt was embeedded in their wounds. These wounds probably were not sustained inside the bus. The bus interior had little evidence of body contact, and the amount of blood (a small splattering near the right sidewall and roof area) was negligible. On the outside of the bus, however, blood, tissue, creasing, and surface marks on the top right-rear side indicate contact with at least one occupant. Passenger 5, who survived, had a lacerated pelvic area and a fractured pelvic bone. She was not in the impact area, and if she had been restrained, she would not have been ejected and her injuries might have been less severe. Passengers 6 and 9 died at the scene. Passenger 6 had two fractured thigh bones, a penetraing injury to the chest, and multiple lacerations and abrasions. Passenger 9 sustained a severly lacerted scalp, multiple bruises, and his left leg was almost severed below the knee. Passengers 6 and 9 were both on the perimeter of the impact area. Lapbelts would have prevented their ejection. They might have been injured by the lapbelt, and sidewall of the bus, or contact with the other passengers. However, they would not have received the massive external injuries that were inflicted during and after the ejection, and their chances for survival might have been better.
The Safety Board concludes that if the unrestrained passengers had been wearing the avilable lapbelts, none of them would have been ejected: Prospects for survival might have been better for three of the children who were killed (passengers 6, 8, and 9). Two of the children who survived (passengers 3 and 5) might have received less severe injuries. One seriously injured child who survived (passenger 4) might have been killed, depending on her position on the bench seat. For two children (passenger 1, who received minor injuries, and passenger 7, who was killed), the outcome probably would have been the same.
Lapbelts in Small School Buses -- On April 1, 1977, the National Highway Traffic Safety Administration (NHTSA) amended the Federal Motor Vehicle Safety Standards (FMVSS) to require that passenger seats in small post-1977 school buses (buses manufactured after April 1, 1977, with GVWRs of 10,000 pounds or less) be equipped with lapbelts. NHTSA Highway Safety Program Guideline #17, December 2, 1992, states:
In 1983, based on several Safety Board school bus accident investigations, the Board concluded that although the overall safety record of school bus transportation in this country had been good, the protection of school bus passengers in crashes was still a matter of intense concern. On September 28, 1983, the Safety Board recommended that the Governors of the 50 States and the mayor of the District of Columbia:
According to the responses received, only six states (Louisiana, New Jersey, New Mexico, Virginia, Washington, and West Virginia) require the use of lapbelts on small school buses. The Snyder accident demonstrates that although lapbelts probably will not protect occupants in the impact area, the use of lapbelts may be beneficial to occupants outside the impact area or on its perimeter. Therefore, the Safety Board reiterates Safety Recommendation H-83-39 to all of the original recipients except the six States in compliance.
A 1989 safety study, Crashworthiness of Small Poststandard School Buses, states:
Since the adoption in 1977 of Federal Motor Vehicle Safety Standard 222 regarding school bus passenger seating and crash protection, there has been a reduction in school bus occupant fatalities and injuries. However, the technological advances that have been made since 1977 in occupant protection (both passive and active) for passenger and commercial vehicles have not been broadly applied to school buses. Therefore, despite the outcome of the school bus lapbelt controversy, the Safety Board believes that NHTSA should evaluate occupant restraint systems, including those presently required, for small school buses. (Such systems could include 3-point lap-shoulder restraints and rear-facing seats.) Based on the results of this evaluation, NHTSA should require the installation of those systems that prove to be effective in reducing occupant deaths, injuries, and ejections. Also, the Safety Board believes that NHTSA, in cooperation with the National Association of State Directors of Pupil Transportation Services, should identify design or equipment modifications that will reduce the view obstructions in school buses. (Equipment modifications could include video cameras.) (pps.30 -- 35)
CONCLUSIONS (Webmaster's note: Only two of the ten conclusions are cited here.)
#9) When the accident occurred, the eight children who were ejected were not wearing their lapbelts and the school busdriver was not wearing her lap-shoulder restraint.
#10) If the unrestrained passengers had been wearing the available lapbelts, none of them would have been ejected: Prospects for survival might have been better for three of the children who were killed. Two of the children who survived might have received less severe injuries. One seriously injured child who survived might have been killed, depending on her position on the bench seat. For two children who received minor injuries and one child who was killed, the outcome probably would have been the same. (pp. 42)
