1.0 INTRODUCTION

Safe transportation of children while travelling to and from home and school is a matter of concern to all involved - parents and students, school officials, transportation companies and government agencies. Over the years in Canada, much of this transportation has been on school buses which have been specifically designed for this purpose and which must meet a number of federal and provincial government safety standards. In addition to these equipment standards, provincial and territorial governments and school boards have adopted various measures for driver qualification and training, special rules of the road for school buses and training of pupils on how to use school buses safely.

Notwithstanding these measures, there continues to be a high level of interest in ways to improve the safety of pupil transportation. The purpose of this paper is to provide a summary of school bus accident and injury characteristics, standards applying to school buses and their operation, and the results of studies relating to school bus safety. In addition, the potential effectiveness of various other measures that have been proposed to improve the safety of school bus users is discussed (e.g. seat belts on school buses).

This information is being used by Transport Canada to assess the need for additional school bus safety standards and will hopefully be useful to others interested in bus safety.

2.0 CURRENT SCHOOL BUS SAFETY STANDARDS

2.1 Canadian Safety Standards
The Motor Vehicle Safety Act requires that new or imported vehicles comply with all applicable safety standards. There are, at present, 35 federal safety standards which are applicable to school buses (Appendix A). These include a number of stringent occupant protection safety standards which are applicable to school buses (Appendix A). These include a number of occupant protection safety standards which were introduced in 1980: increased body joint strength (CMVSS 221); improved retention and emergency exits (CMVSS 217); improved occupant protection (CMVSS 222) and better fuel system integrity (CMVSS 301).

The more stringent standards for school bus seats were based on extensive testing conducted in the U.S. and Canada. Occupant protection is improved by containing students between high-backed, heavily padded, closely spaced seats. A high, padded barrier replaced the old steel post and the modesty panel which was ahead of the front row of seats. Performance criteria introduced to ensure that seats absorb a specific amount of energy if struck by an occupant during a collision. The method of attaching the seats to the floor and attaching the seat cushion to the seat frame was upgraded. These features are collectively referred to as the "compartmentalization" concept. Canadian motor vehicle safety standards do not require the installation of seat belts for passengers (see Section 3.3.1 for further information).

2.2 U.S. Safety Standards
U.S. occupant protection safety standards are generally the same as those in Canada with the following exceptions which apply to smaller school buses (4 536 kg (10,000 lbs) or less).

1. The U.S. regulation FMVSS 222, which became effective April 1, 1997, requires that a lap belt be installed at each passenger seating position.

2. In Canada, a padded barrier must be installed ahead of each seat that does not have another seat within 610 mm of the Seating Reference Point (SRP)*. This barrier is not required in the U.S.

3. The Canadian regulation specifies a head protection zone which must be kept clear of obstructions or be padded, and a spacing between passenger seats. This requirement is not mandatory in the U.S.

2.3 Provincial and Territorial Government Standards and Policies ________________________

* "Seating Reference Point" is the manufacturer's design reference point that establishes the rearmost riding position on the seat and simulates the position of the pivot centre of the human torso and thigh.

Provincial and territorial governments are responsible for regulations, standards or policies regarding the operation of motor vehicles, including school buses. These include driver and vehicle licensing, maintenance and inspection, and traffic laws governing school buses. The following summarizes our most recent information in this regard, obtained from provincial and territorial government representatives of the Canadian Council of Motor Transport Administrators (CCMTA).

In all jurisdictions, school bus drivers must pass specific medical, knowledge and road skills tests prior to licensing. In addition, periodic re-examination is required in most jurisdictions. The majority of provinces also require school buses to stop at all railway crossings. School buses in all jurisdictions must undergo at least annual safety and mechanical fitness inspections as part of vehicle licensing. These inspections are reasonably consistent in all jurisdictions. Traffic is required to stop in both directions for loading and unloading when red lights are flashing, although some provinces make exceptions for divided roadways. Individual provinces or territories also have additional requirements for school bus equipment, such as automatic stop arms or supplementary mirror systems.

Most provinces prohibit standees on school buses, and the remaining jurisdictions discourage the practice. No province or territory requires seat belts (other than for the driver) to be installed in school buses, although it is left to the discretion of local school boards or boards of education. In most jurisdictions, seat belts would have to be worn if the bus were so equipped.

Source: Background Paper, pps. 1-3

3.3 Seat Belts in School Buses

3.3.1 General
CVSSS 222 "School Bus Passenger Seating and Crash Protection" was proposed in the Canada Gazette Part I on February 4, 1978, to become effective September 1, 1978. The proposal would have required that seat belts be installed at each designated seating position in all smaller school buses (gross vehicles weigh rating of 4 536 kg or less) and that seat belt attachment points be provided on seats in school buses with a weight rating greater than 4 536 kg.

Due to the many adverse representations received from manufacturers, school boards and operators, the seat belt and seat belt anchorage requirements were withdrawn. This was done with the understanding that there would be a thorough review of the effect that seat belts would have on school bus occupant safety and further investigation of the areas of concern raised by commentators to the Part I. Those commenting questioned the following:

a) cost-benefit ratio due to the low number of accidents involving school buses;

b) adverse effect of seat belts on the undeveloped bone structure of young children;

c) operational problems such as replacement of damaged belts and maintenance of belts;

d) difficulty of monitoring students to ensure that belts were worn and properly adjusted;

e) potential for using belts as weapons to strike another student; and,

f) concern about liability of the operator or driver if the belts were not worn and/or were improperly adjusted if the bus was involved in an accident.

CMVSS 222 without the seat belt requirement became effective September 30, 1980.

3.3.2 Full Scale Crash Tests
In late 1984, Transport Canada performed full-scale crash testing on three different sized school buses, to measure the effect that seat belts might have toward improving occupant protection (Reference 5). The buses used were a 66-passenger, full size Blue Bird conventional type, a 22-passenger Thomas Minotour and a 20-passenger Campwagon van conversion.

Each bus contained six test dummies, instrumented to record forces on the head, chest and femurs. These dummies were meant to represent older public school students. Three of the dummies were secured in place with a manually adjusted lap belt and three were left unrestrained. The buses were crashed into a concrete barrier at a speed of approximately 48 km/h (30 mph) to simulate a severe frontal collision.

For an analysis of the results, the Head Injury Criteria (IC) value and chest acceleration were used. The HIC value is a measure of head accelerations and their duration. An upper limit of 1000 is used as the threshold above which serious injury or death can be inferred. An upper limit of 60g* for longer than 3 milliseconds is the threshold used to infer the severity of the chest injury.

In general, the results indicated that the belted dummies experienced more severe head and lower chest accelerations that did the unbelted ones. Furthermore, from the film data, the belted dummies showed more severe rearward neck extensions mainly due to the angle at which they struck the seat ahead of them. Dummies restrained by seat belts in both the Thomas and the Campwagon buses experienced HIC values in excess of 1000, whereas the unrestrained dummies experienced HIC values less than. In the large Blue Bird bus, all dummies experienced HIC values of less than 1000, but those restrained by seat belts had values approximately three times greater than those for the unrestrained ones. ________________

* "g" is the acceleration due to gravity

These differences can be explained by the fact that the restrained dummies pivoted about the lap belt, striking their heads severely on on the seat back in front. The dummy heads compressed the seat back padding to such a degree that they hit on the steel structure underlying the padding.

These tests also suggested that if seat belts were to be added to school bus seats, the entire seating system should be considered. Such consideration led to the school bus seat development program.

3.3.3 School Bus Seat Development Study To investigate possible methods of improving the protection for school bus occupants, a project was initiated to design, construct and test five different seating concepts, each employing a restraint system (lap belt, lap-shoulder belt or harness). Modifications were made to a standard .99 m (39 inch) wide Blue Bird seat with manual seat belts in order to meet the specific requirements for each of the new concepts. In addition to these five new designs, a standard Blue Bird bus seat with lap belts was also tested to provide baseline data for comparison purposes.

The five new seat designs were the following:

1) Contoured padded seat back and lap belt combination. This design included additional padding on the top and rear of the seat back.

2) Less aggressive seat back and lap belt combination. The top portion of the seat back frame was modified to allow greater seat back deflection when struck from the rear.

3) Rearward facing seat with lap belt. The seat was turn to face the rear of the bus and the seat back was increased in height.

4) Three-point restraint system. This seat incorporated an automotive type lap and shoulder belt requiring that the seat frame structure be considerably reinforced.

5) Multi-point restraint system. This seat incorporated a harness type restraint, consisting of a lap and two shoulder straps. The seat frame structure was again considerably reinforced.

All seat belt systems, with the exception of the unaltered seat and the multi-point restraint system, used automatic locking retractors.

The seats were tested on the Hyge impact test facility at the Defense and Civil Institute for Environmental Medicine (DCIEM) in in Toronto. Both head-on and oblique (30 degrees from head-on) tests were preformed at a deceleration of 30g's from 48 km/h. Instrumented test dummies were used to acquire test data for head and chest acceleration, femur (thigh bone) and seat belt loads. High speed filming of each of the tests was also done to assist in the analysis of the results.

The test results can be summarized as follows:

1) Contoured padded seat back. The results were essentially the same as those for the standard unaltered seat.

2) Less aggressive seat back. The peak head acceleration was significantly lower and the chest acceleration was somewhat lower than for the unaltered seat. However, the Head Injury Criteria (HIC) value was essentially the same as that calculated for the unaltered seat.

3) Rearward facing seat. This seat showed a significant reduction in all recorded injury criteria, compared to the standard unaltered seat.

4) Three-point and multi-point restraint systems. Both these systems significantly reduced the head acceleration and HIC, but not the chest acceleration.

The following conclusions were reached from this test program (Reference 6):

i) The rearward facing seat was effective in reducing all injury levels to acceptable values.

ii) The upper torso restraint on the three-point system reduced the HIC value to acceptable levels but did not improve the peak chest acceleration. However, if a three-point restraint system were used, it would be imperative that all occupants wear seat belts, since the increased stiffness of the seat structure required for three-point seat belts would cause additional injury to unrestrained occupants in a collision.

iii) The two systems which used modified forward facing seats and lap belts were not effective in reducing HIC to acceptable levels.

iv) The multi-point seat belt system was cumbersome to use the permitted submarining (sliding under the belt) of the test dummy.

v) The location of the retractors on the lower seat frame must be re-examined to prevent possible damage by knee contact from the rear.

3.4. Rear Facing Seat Demonstration Project

3.4.1 Assessment of Performance of Seat and Seat Belt System
In order to investigate the concept of rear-facing seats further, a demonstration project was initiated. Three school buses Three school buses were purchased and modified by installing rearward facing seats with lap belts. In addition, large mirrors were installed on the rear wall of the bus in an effort to allow the driver to establish eye contact with the rearward facing students.

The buses were loaned to four school boards across Canada for their use during the 1987-88 school year. The buses were run on regular school bus routes to determine the acceptance of the seating arrangement by students, drivers, teachers, parents and school officials.

A 22-passenger bus was loaned to the Toronto Board of Education for operation by their transportation contractor, Allway Transportation Systems. This bus was operated in a large urban area throughout the year.

A 48-passenger bus was loaned to School District 36, in Surrey, B.C.. This bus was operated in a combination urban/rural environment.

A 66-passenger bus was loaned to the Kings County District School Board in Kentville, Nova Scotia for the period from September 1987 to January 1988. This bus operated in a mainly rural setting, in the Annapolis Valley area. From February to June 1988, the bus was used by the Northside Victoria District School Board, on Cape Breton Island. Here it operated in a environment, over some very hilly terrain.

Operation of the buses and the performance of the equipment on the buses were monitored by Transport Canada throughout the school year. This was done by personal inspections and by talking to both school officials and bus drivers. The following items were noted during the operation of the three buses over the school year.

1. There were three seats belts installed per 99 m seat although very few boards actually carried three students on a seat.

2. There were some complaints of the belts lightening up on rough roads. Retractors of the emergency locking type could be expected to reduce this problem.

3. The belts were routed through plastic guides which protruded about 3" above the seat surface so that they would be easily accessible. However, most of these guides were broken off as a result of the students sitting on them.

4. Any retractors which are used must be designed to prevent small items from falling in into them and causing them to jam. This was not a big problem but it did occur a few times.

5. Some seat belts became twisted when they retracted into the retractor. This did not affect the operation of the belt and the condition was easily corrected. However, retractor re-design should eliminate this problem.

6. The seat belts were too long and should be shortened. This would also lessen the incidence of belts twisting in the retractor housing.

7. Belts tended to fall behind the seat if they were not being uses.

8. Due to the high backed seats, there was a visibility problem for drivers on the right hand side. The driver had difficulty The driver had difficulty seeing traffic approaching from an angle at the right.

9. There were also complaints that the aisle width was too narrow. This was probably a result of the seats being higher, since the aisle was the same width as in the regular buses.

10. The mirrors installed on the rear wall to provide the driver a frontal view of the students proved to be of little use, due to excessive vibration. In one instance, though, the driver commented that the students didn't know he couldn't see them, and the mirror had a positive psychological effect toward improving discipline.

11. There were some complaints that the seats were too close together. This was probably due to the high back also, since seat spacing was spaced almost the same as in a new "normal" bus.

12. There were no incidents of seat belts being used as a weapon.

13. There was one incident where some belts were deliberately tied in a knot. This was the only incident of deliberate vandalism.

14. There were some complaints of students feeling ill because they were facing rearwards. In most cases, they overcame the problem in a few days. The students seemed very adaptable to the rear-facing seat concept.

15. Seat belt usage varied with student age and driver insistence on wearing. Almost all young students wore belts. The wearing rate then dropped off significantly for high school students.

16. Some drivers commented that because of the high-backed seats, they could not see the students and discipline deteriorated somewhat. Others commented that discipline on the bus actually improved. The seat belts and high-backed seats cut down on the visiting and hanging over seat backs. Students complained that they couldn't talk as easily with their neighbours.

17. Parents who had the opportunity to examine the bus liked the concept and thought it was an improvement.

18. One of the operators requested that the rear windows be changed from the tempered glass to laminated glass, as is used in the windshield. For occupants facing the rear, this would be a reasonable approach to follow. Laminated glass does not produce flying shards when broken.

3.4.2 Views of Students, Parents and Drivers
The evaluation of the demonstration buses equipped with rear-facing seats with seat belts involved obtaining information from many of the participants in the project (Reference 7). Questionnaires were distributed to all students who had the opportunity to ride as passengers on the demonstration buses on their regular school bus routes and parents of younger children. The school bus drivers were interviewed either by telephone or in person to discuss their experiences of driving the demonstration buses. I informal discussions were held with small groups of students who were passengers on the demonstration buses. School officials noted any comments received about the buses. Finally, Transport Canada research staff took school bus rides for observation a conversation with students and drivers in each location.

Questionnaire Results
Over 900 students were given questionnaires. Students in grades 6 through 12 completed a student version of the questionnaire while students in junior kindergarten to grade 5 and special education programs took home questionnaires for their parents to complete. To date, 467 questionnaires have been returned, about 50% of the number distributed.

Forty-seven percent of the students who responded to the questionnaires reported that they had problems with the demonstration buses. The major problems were feeling sick (reported by 20% of all student respondents. The major problems were feeling sick (reported by 20% of all student respondents), uncomfortable seat belts (9%) and insufficient space between seats (9%). The reporting of problems was not dependent on students' age, sex or grade level. However, location was a factor as 70% of students in this Surrey reported problems, compared with 43% in King's County, Nova Scotia. When asked specifically about feeling sick, 43% answered in the affirmative.

The apparent safety level of the demonstration bus was on average rated higher than the apparent safety level of the regular school buses. The oldest group of students (17-20) was least convinced of the safety benefits of the demonstration bus compared with younger students (11-16).

Students 11-14 years of age reported on average more frequent seat belt usage on the bus compared with older students, with lowest use shown for those 17 and older. Seat belt use on the buses was similar in King's County and Cape Breton (on average a student used a set belt 6 out of 10 times) but was close to zero in Surrey. About one-third of the students said they favoured the demonstration bus, with greater favourability in both King's County and Cape Breton.

The most common comments about the bus referred to the seats - too high, too close together, etc. - and were given by 15% of students. A further 9% disliked the seat belts, and 10% disliked facing backwards. However, 12% of students commented that they like the bus and felt safer riding on it.

The parent version of the questionnaire was design to obtain information about children from junior kindergarten age (4 years) to grade 5 age (about 10-11 years). Fifteen percent of parents who responded reported that their children had some sort of problem concerning the demonstration bus. The major problem (8%) was children feeling sick on the bus. When asked directly about sickness, 21% reported that their child had felt sick on the bus. Seventy-five percent of parents favoured the demonstration bus. Parents in the Toronto Board rated regular buses (which are equipped with seat belts in this Board) safer than did other parents and were least favourable towards the demonstration bus. Some parents (10%) expressed concern about the safety of rear-facing seats due to concern about the safety of rear-facing seats due to the driver's inability to supervise the children, and a lack of understanding of the purpose of this seat configuration. Other parents mentioned a concern about the safety of seat belts and childrens' ability to unfasten them in emergency situations, and the need for bus monitors to ensure correct seat belt usage.

In all, 16 school bus drivers had the opportunity to drive one of the demonstration buses. Interviews were conducted with these drivers to discuss the issues of student conduct, seat belt use, seat belt problems and driver attitude toward the demonstration bus. Information was also obtained concerning driver experience and any field trips that occurred.

Student conduct on the buses seemed to vary depending on the driver and his or her tolerance for noise, movement, etc., as though students were very much aware of their driver's limits and behaved much the same as usual, regardless of the type of bus. Student motion sickness was not mentioned as a big problem. In fact, most drivers did not receive any complaints at all from their passengers. As noted in Section 3.4.1, there were some problems with the seat belts. Belts got twisted and jammed in the retractors. Seat belts seemed to tighten up very easily and too tightly for the smaller students.

Seat belt usage was estimated at 90-100% for primary and elementary level students. For junior high and high school students, the seat belt usage rate was about 40-75%, except in Surrey where it was close to zero.

Most of the drivers were either slightly favourable or favourable toward the demonstration buses. Those who were favourable in their opinions were those who seemed to have more of a problem with student discipline on the bus. All drivers expressed concern about the inability to supervise the children as well as on a regular bus, but for those with stricter rules of behaviour for students, this was not a major problem.

Although discussion groups were held with students before the questionnaire results were examined, the discussions basically confirmed the questionnaire results. Young students generally favoured the demonstration bus, liked the seat belts, liked riding backwards and felt safer on the bus. Older students did not like riding backwards, found the seats too close together and did not like the seat belts. It should be noted that with three belts on a seat, the seat was definitely uncomfortable for older, larger students. Perhaps, with only two belts per seat and somewhat wider spacing between seats, the reaction from older students would be more favourable.

Finally, researchers' observations made while riding on school bus routes confirmed the drivers' estimates of seat belt usage. Seat belt use declined as student age increased. The comments from older students about the close fit in the seats, lack of legroom and belts sticking into them were also confirmed.

3.4.3 Other General Issues
During the interview and discussion process, some other issues were raised about school bus transportation in general. These included the role of driver training and awareness in reducing accidents: student monitors for control of students around and inside the bus; more rigorous control of drivers passing stopped school buses; radios for buses; and bus routing reviews to minimize students crossing roadways. All of these are potentially useful measures, but the extent to which they may currently be in place and their potential safety effectiveness are not presently known.

4.0 EFFECTIVENESS AND COST OF POSSIBLE FUTURE CHANGES

4.1 Seat Belts in School Buses
The potential safety benefits of seat belts on school buses are not known. The results to date of testing and in-depth accident investigations in Canada and the United States suggest the unique (to school buses) seat spacing and padding requirements and other factors such as the relatively large size of buses, result in very few fatalities or serious injuries. Although lap seat belts in automobiles are estimated to reduce the likelihood of death or serious injury by 20 and 25 percent respectively, it is not known if the same would be true for school buses.

Cost estimates to incorporate each design into a school bus were obtained from the Blue Bird Body Company in Fort Valley, Georgia. The estimated increase in cost to build a seat which incorporates the changes is tabulated in Table 2.

These cost figures did not include any provision for other modifications indicated as a result of the testing program (Reference 6). The retractor, located at knee level, would have to be protected from damage. The rearward facing seat would have to be reinforced somewhat to lessen the rearward deflection of a seat in a collision. Such cost would depend upon the final design chosen.

(1) These figures are increased costs for changes made to basic Blue Bird seat. These are Blue Bird's wholesale price to their distributors and do not include a distributor mark-up.

(2) These costs are actual costs for standard items from Bendix Restraint Systems. These retractors are stock items and there is no discount for volume quantities.

3) This would be wholesale cost to school bus distributor.

(4) These figures are based on 3 belts per seat.

Note: Cost to install the lap belt with retractor on existing unaltered seat would be approximately the same for the contoured-padded seat.

These designs and costs were based on a specific manufacturer's seat. Other manufacturers would have to modify the designs to suit their own manufacturing methods.