Paratransit and School Bus Accident Investigation Issues & Answers

TOPIC ONE: Compartmentalization Compromised: The Issue of School Bus Passenger Safety

By Dr. Ray Turner,
School Bus Accident Reconstruction

School Buses Size and Weight Makes All the Difference

School buses have a unique history of design and construction that over many years has proven that the larger school buses are very crashworthy for their student passengers. The National Highway Transportation Safety Administration (NHTSA) has enacted many Federal Motor Vehicle Safety Standards (FMVSS) of which at least 55 apply to school bus construction and crashworthiness. The FMVSSs as contained in Title 49 CFR Part 571, apply specifically to school bus occupant protection including FMVSS 220 for School Bus Rollover Protection, which establishes performance  requirements  for  reinforcing  the  school  bus  body  structure  to withstand  forces  encountered  in  rollover  crashes. FMVSS 221 addresses School  Bus  Body  Joint Strength and establishes performance requirements for the strength of the body panel joints in the school bus and how the bus should perform in a collision. FMVSS 222--School Bus Passenger Seating and Crash Protection establishes performance requirements for school bus passenger seating and restraining barriers.

Both Type A and B vans or buses are under 10,000 GWVR and must have seatbelts for occupant protection. Neither type relies on compartmentalization as identified in FMVSS 222--School Bus Passenger Seating and Crash Protection. Type C or conventional school buses having a seating capacity of up to 72 elementary students or 41 middle or high school pupils must comply with FMVSS 222. This bus type consists of a body installed upon a flat-back cowl truck chassis with a GWVR of more than 10,000 pounds and an engine located forward of the windshield. Empty Type C buses weigh in at 22,000-25,000 pounds. The Type C entrance door and driver’s seat are aft of the front axle. Some Type C buses have a shorter chassis and body with fewer seat rows and a reduced seating capacity. Most have the standard 13 rows of seats on both sides of the aisle with a narrow 16” aisle separating 39” wide seats. Seat rows are set closely as possible from the back of the bus forward to assure so that compartmentalization will better protect students in a collision. The only seat belt and shoulder harness on Type C is for the driver. Compartmentalization is assumed to protect all of the students on board.

Still larger Transit-style or “Type D” school buses also comply with FMVSS 222. With a body installed upon a truck chassis and an engine mounted in the front, midsection, or to the rear. Type D or transit buses have GVWRs well over 25,000 pounds empty. They have up to 84 elementary school student seating capacity. The entrance door and driver’s seat are forward of the front axle. Type D buses have the same 16” aisles and 15 rows or more of 39” wide seats in tandem. The only three point seat belt-shoulder harness on the bus is for the driver. Compartmentalization in these buses is also designed for all students without the use of any seat belts.

The FMVSS 222 or School Bus Passenger Seating and Crash Protection for School Buses is intended to reduce the number of deaths and occupant injuries resulting from collisions of school bus occupants against structures outside the bus. Compartmentalization alone, however, will be shown below as not protecting students from rear end collisions, lateral collisions and rollovers as well as non-collisions during sudden driving maneuvers such as hard braking, sharp turning, or students being airborne during bus rear end elevation over rough roadways. The conventional interpretation of FMVSS is that by means of compartmentalization large school buses interiors will provide occupant protection so that children are protected without the need to buckle up.1

Arguments FOR School Bus Compartmentalization Supporting Student Passenger Safety

The argument FOR school bus compartmentalization for Type C and D buses is based on these data:

The larger buses have a considerably larger mass than the majority of vehicles that collide with them giving student occupants a life-saving advantage. Because of the Type C and D construction school buses have different crash force distribution during vehicle-to-vehicle collisions.

Type C or D buses have high ground clearance with Delta V forces at the point of impact, or the point of maximum intrusion, occurring under the bus floor while the other vehicle underrides the passenger compartment. Bus passengers are thereby spared the highest crash pulse and the best ride down conditions compared to the others in the opposing vehicle.

US Fatality data since 1988 reveals that there were 416,000 fatal crashes of which 1,265 were school bus related. From 1988 to 1997 there were 115 fatalities on Type C and D school buses. Of the school bus collision fatalities 64% or two-thirds were passengers in the other, smaller vehicle. 27% of the school bus fatalities occurred outside the school bus—usually in the danger zone or an area some 10 feet on both sides or to the front of the bus. 10% of the fatalities were school bus occupants where compartmentalization may have minimized other fatalities and/or reduced other bus passenger injuries. Of the 10% fatalities in the bus 2% were drivers and 8% were student passengers. Since school bus drivers are always required to wear their three-point lap/shoulder belts compartmentalization for school bus drivers does not apply.

The Most Harmful Events (MHEs). For those 115 school bus fatalities cited above the MHEs came from 29 crashes with other vehicles, 14 fatalities from a collision with fixed objects, 6 fatalities from school bus rollovers, and 66 MHEs from all other bus locations.

Types of Vehicles in School Bus Collisions. Fatalities in the two-vehicle crashes occurred with large trucks with equal or greater GWVRs than the Type C or D buses 89% of the time. Light Trucks accounted for 7% of those school bus fatalities with the remainder coming from school bus collisions with passenger cars and other vehicles.

Direction of School Bus Collisions. Heavy truck frontal collisions with school buses accounted for 83% of the MHEs, Right-side lateral collisions were 10%. Left side collisions were 5%. 2% were rear-ending collisions. If we can assume that the same locations of collisions with lighter, passengers vehicles will mostly be from the front of the bus, with much fewer lateral collisions from either side of the bus and only 2 out of 100 being struck from the rear end—what does compartmentalization do then to contribute to passenger safety under those conditions?

For Type Two Collisions, or collisions of occupants within vehicles, compartmentalization provides passive occupant protection with energy absorbing, well-padded high seat backs that are strong and closely spaced in rows within the bus.

Arguments AGAINST School Bus Compartmentalization as Passenger Protection during Collisions

“It is difficult, if not impossible, to develop ways to protect school bus occupants in catastrophic crashes, such as those involving trains and heavy trucks. The crash forces in those crashes are so great that any reasonable structural design cannot maintain the integrity of the vehicle, which is one critical component of occupant crash protection. (National Transportation Safety Board)”2

We may therefore conclude that in catastrophic collisions compartmentalization does not provide sufficient student passenger safety for some or all passengers. Therefore in all other less-than-catastrophic collisions how well does compartmentalization work for all student passengers as it was intended?

The National Transportation Safety Board (NTSB) investigated a school bus accident in Conasauga, Tennessee, in which a school bus was struck on the passenger side by a locomotive traveling 51 mph. The NTSB concluded that sidewall components, such as the overhead storage racks, seat frames, and sidewalls, were not designed to be energy-absorbing; These structures could cause injury to occupants by lateral  movement during a side-impact collision.3 As a result, the NTSB  issued Safety Recommendation H-01-40 to NHTSA:

“H-01-40. Develop and incorporate into the Federal Motor Vehicle Safety Standards performance standards for school buses that address passenger protection for sidewalls, sidewall components, and seatframes.4

We may further conclude that no such sidewall protection, school bus sidewall components or seat frames have yet been implemented that would protect students from any lateral collisions. Seat frame strengthening or reinforced seat frames have not been developed in the industry since this recommendation was made. Overhead storage racks are no longer manufactured in newer buses. There are many older buses that have storage racks that endanger student passengers during collisions.

In a school bus accident in Central Bridge, New York5 the NTSB found that seat cushions came loose during impact. The Board subsequently concluded that the school bus passengers, whether lap belt-restrained or unrestrained, may have sustained more severe injuries because the seat cushion bottoms were unlatched. The NTSB made Safety Recommendation H-00-29 to NHTSA:

H-00-29. Modify   the   Federal   Motor   Vehicle   Safety   Standards   to   include   the requirement that school bus seat cushion bottoms be installed with fail-safe latching  devices  to  ensure  they  remain  in  their  installed  position  during impacts and rollovers. Because enhanced performance for    sidewalls, sidewall components, seat frames, and seat cushion fixation are critical for occupant safety in many accident scenarios, the Safety Board urges speedy action on these recommendations.6

NHTSA enforcement of seat cushion bottom securement to the seat frame has been adopted by school bus manufacturers. However, this leaves many older buses in the fleet not meeting that safety standard. When seat cushions become loose during bus lateral collisions or rollovers then compartmentalization is compromised. Without a seat cushion under them those students have no other safety measure to protect them from injury during collisions. Loss of collision integrity of the seat back, the seat cushion and/or the seat frame means compartmentalization cannot work as intended during all rollovers or many lateral collisions.

School Bus Compartmentalization Is Not What It Seems…

Does compartmentalization compromise passenger driver safety during school bus collisions? When would compartmentalization work or not work to save student lives? If compartmentalization cannot save passengers lives in catastrophic collisions, and the data in this article cites only fatalities, then how many more major or minor student injuries would compartmentalization prevent or not prevent? Heinrich’s Pyramid7 predicted the ratio of fatalities to major and minor injuries in industry in general. Heinrich placed fatalities at the top of his pyramid. Mollenhauer8 in 1998 modified Heinrich’s Pyramid to represent fatalities and lesser injuries with respect to collisions for both cars and trucks. The Mollenhauer truck injury data is a modified Heinrich Pyramid. The data is comparable to Type C and D school buses which are constructed of heavy truck chassis.(See Figure 1).

School industry leaders and the school bus industry as a whole tend to view compartmentalization as a safety standard fitting all collisions, all students, students in various positions in or out of their seats, students standing, students facing to the rear and other positions and not with their feet flat, facing forward with hands on lap.

 The Compartmentalization Envelope (CE) is an envelope of protection--not a safety attitude--for school bus manufacturers, transportation supervisors, directors, and bus operators. Here is what the Compartmentalization Envelope (CE) literally means:

The CE is a cubic volume of space starting at the top of the seatback where the student is seated with a plane formed from to the top of students seatback to the next seatback in the row immediately in front. The end of the student’s seat cushion near the bus wall is one of the side planes of the CE extending from the top of the student’s seatback down to that student’s seat base and then extending plane forward to the seatback side and cushion base of the row immediately in front. At the other end of the student’s seat cushion adjacent to the bus aisle is the other side of the (CE) plane that also extends from the top of the student’s seatback to the his seat cushion base and then extending plane forward to the seatback side and cushion base of the row immediately in front. Visualize the base of the CE cubic space as being level plane formed by the underside of the student’s seat cushion (not the bus floor) and extending forward at that level to the seat base of the seat immediately in front. The student’s 39” wide seatback is the back plane of the volume and the seatback immediately in front is the front plane of the CE cubic area. Multiple CEs are formed between each pair of adjacent seats in the school bus.

Further, because seatmates sharing the same CE may collide with one another during a collision the CE should be for one student passenger only so that there would be no other students with which to collide. If other students are present then it is problematic whether the CE can be effectively shared with seatmates. Lastly, any student secured with any lap belt or harness is by definition not protected within the CE since compartmentalization was defined according to NHTSA as not requiring students to use seatbelts.(See NHTSA citation #1 above.)

Within the compartmentalization envelope (CE) what size of students are best protected by the high-backed, well padded seats at their back and the seatback facing ahead?

The problem of Child Safety Seats. Smaller children with shorter legs that do not extend over the seat cushion and reach down below and outside the base of the compartmentalization envelope have the best protection. However, infants and small children under 40 pounds bodyweight are required to be secured on the school bus using Child Safety Restraint Systems (CSRS).9

Children using CSRS are not protected by compartmentalization because they are secured by a seat belt through the CSRS belt channel. The belt must be firmly secured to the seat frame. The Compartmentalization Envelope (CE) does not apply to any students using Safety Vests that require a cam strap securement behind them and around the back of their own seats. Children seated in booster seats on specially designed bus seats are secured with a three-way harness that is anchored to a reinforced bus seat frame. Booster seats with built-in harnesses are not afforded CE protection because they are secured with a seat belt.

Lateral Collisions and the Student’s CE. Lateral collisions with students of any size will eject them from their CE and into the aisle or across the aisle against their fellow students who are seated in the row opposite them when moving toward the point of impact. Some students during lateral collisions are ejected from their CE and slammed against the opposite interior bus wall.

Rear End Bus Collisions and the Student’s CE. During a rear end bus collision those students whose heads do not extend above their seatbacks will derive a benefit from their seatback acting as an effective back and neck restraint to reasonably assure their safe ride down. Older elementary students, or any middle and high school students are vulnerable to neck injuries from neck extension backward over their own seatbacks. In a high intensity rear end collision some students may ramp up and out of their seats backwards toward the point of impact. Students with neck extensions may also be those who are ramped backward and have exited their CEs. They, too, were not adequately protected from injury.

Frontal Bus Collisions and Their CE. When student heads are higher than the height of both seat backs—the seatback in front and the one on which they are seated—during a frontal collision those larger students are likely to suffer neck injuries suffering from neck flexion forward and over the seatback in front of them. Larger students in frontal collisions tend to ramp up and over the seat while moving toward the point of impact. When students ramp up in either direction (forward or backward) their CE is not working.

Students Not Properly Seated, Facing Forward and Their CE. Any students not seated facing forward with bodies turned toward the aisle, toward their bus wall, or facing rearward against the direction of bus movement, or kneeling in the seat facing forward or to the rear, or standing and facing in any direction while the bus is moving or other improper seating positions—all these students are outside their CE. For those ejected only from their seats but who remain within their seat bus row all other surfaces surrounding them are not padded surfaces and will not protect students colliding with bus walls, floors, seat frames, seat legs, the space under the seat in front or the space under their own seat. Those fortunate enough to remain within their CE may collide with their fellow seatmates, with backpacks, band instruments, lunch boxes, or books not secured to cause injury to those students in the collision mix.

Compartmentalization Compromised

Thirteen rows of seats should each provide a CE for student passenger safety during a collision right? What about the following rows or passenger placements on the bus?

Students with Front Row CE. Passenger side front rows face the stairwell stanchion with little or no padding on the frame and a metal modesty cover for the student seated there. The driver side front row seated students fare no better with the same type of stanchion in front of them and forward to the back of the driver’s padded seat—none of which affords a modicum of padding as do all other padded seat backs in the seat rows behind. During frontal collisions students may be ramped up or ejected into the stanchion opening into the driver or on the passenger side row pummeled down into the stairwell. Damaged front exit doors allow their ejection from the bus. (Conclusion: Students in Front Rows Have NO CE.)

Students with Back Row CE. Passengers seated in the rearmost seat rows have the rear exit door and windows behind them. During a rear-end collision there are no students to ramp over onto them from the rear. However, student in rows forward from them may be ramped back into them. Students seated in the last row may be ejected from the bus through the rear aisle windows or from a rear door when that door integrity is compromised. Further, during that same rear end collision the students seated in the last rows receive the greatest amount of intrusion, are at or nearest the point of impact and experience the largest Delta Vs. (Conclusion: Students in Back Rows Have No CE.)

CE for Students in Seat Rows Distant From the Bus Center of Gravity. Students seated in rows progressively further away from the bus center of gravity (CG) are subjected to increasing G forces. During a collision causing the bus to yaw, to slide sideways or to spin without a rollover those students seated in rows most distant from the bus CG are ejected across the aisle to the adjacent seat row or are pressed against the bus wall on their side of the bus with other students ejected into them from the opposite row. (Conclusion: On either side of the bus aisle those students are outside of their protective CE or some of those students suffer an intrusion by others into their CE.)

Students in Seat Rows When Airborne Have No CE. Students are the most vulnerable to lateral displacement outside their CE during sharp turns and bus off-tracking at modest speeds. Onboard bus videotapes reveal that when the bus hits a dip or a speed bump or “curb hops” even at speeds under 10 MPH students will become airborne. (Conclusion: When airborne and off their seat cushions those students are outside or above their CE.)

CEs and School Bus Passenger RSIs. When buses are driven at normal speeds, and with no collisions, students in the last rows are jostled hard and continuously. The level of jostling is comparable to a continuous low-G bus collision for them. Adult bus attendants assigned to the back of the bus experience continuous jostling and have legitimately complained of back and neck Repetitive Stress Injuries (RSIs). Research on passenger seat displacement on buses using accelerometer data is critically needed. Passengers may receive RSIs when seated in the back of the bus when subjected to lateral forces that remove them from their CE while still remaining in their seat rows. (Conclusion: Minor up to major Repetitive Stress Injuries (RSIs) can and do occur because of repeated passenger displacement off their bus seats.)

CEs and Bus Passenger Seat Cushion Displacement. Higher Delta V bus collisions have caused some passengers to experience seat cushion failures as they return to their seating space after being airborne and out of their CE.10 Some students are pinned down within the seat frame after the seat cushion was ejected from that same seat frame.10 Other students may be injured by ejected seat cushions that become projectiles inside the bus or inside the seat row during ride down. (Conclusion: Students with seat cushion failures are extended below or above their CE. Ejected seat cushions can be a danger to all students on a bus in a collision.)

CEs for Passengers In Wheelchairs Does Not Apply. Lift bus lateral movements over rough roads and sharp turns all combine to physically challenge the already physically challenged. Injuries abound with students using manual or power wheelchairs when they are “jostled,” tipped sideways, or ejected from their wheelchair if improperly secured.5 Wheelchairs users do not have a CE since their chairs are secured with four straps connecting the equipment with bus floor tracking and the student is secured with occupant restraint with a lap and shoulder belt system in place. (Conclusion: Students Using Wheelchairs Do Not Have Their CE.)

CE for Wheelchair Users Who Transfer to a Bus Seat. Wheelchair users who transfer to a school bus seat nearby may not be able to maintain their seated position on the bus without a three-way lap and shoulder belt built into a special, highly reinforced school bus seat. With no lap belt or a vest secured with a cam strap to their seat backs some of these students will slide out of their seats onto the floor during normal braking or especially when the bus is involved in a minor collision. (Conclusion: Students Using Wheelchairs When Transferred To A Seat May Not Have CE without added belt securements. Yet with belt securement students no longer receive a CE).

Students in School Bus Rollovers are Protected by CE? During school bus rollover collisions the CE for some occupants does not protect them. Some students receive compound collisions to their bodies when ejected from their seating area. Other students receive ejected students colliding against them and the bus wall. The first collision sequence is the crash pulse may occur in 1/10th of a second as the students onboard farther away from the point of impact are ejected from their seat toward passengers seated in rows nearest the point of impact. Students are slammed directly into their neighbors in the opposite row as they move toward the lateral point of impact or are pressed hard against the wall nearest the point of impact. The entire nation witnessed this instant process when ABCNEWS.com aired on November 6, 2006 on the World News a bus 900 rollover to the bus driver side.11 When a compound rollover occurs the combined weight of students ejected across the aisle shifts the bus center of gravity. This sudden student bodyweight shift combines with the energy of the striking vehicle for the bus to rollover. The second collision sequence occurs when all students fall together “down” to the bus ceiling. The bus ceiling is not a passenger friendly surface. Like the walls, the floor and other bus surfaces these surfaces cause injuries. Students may fall six to seven feet from their seat rows against the ceiling head-, feet- or side-first during rollovers and outside their CEs. If the bus point of rest is upside down there remains the third collision sequence that occurs when students who are conscious and ambulatory attempt to evacuate an upside down bus. Slips, trips and falls and collisions with other students can and does cause further injuries. Should the bus rollover further to 1800 a fourth sequence would occur with students falling from the ceiling to the other side of the bus. Additional quarter-turn rollovers would put students in harms way as though they were clothing tumbling in a clothes dryer. (Conclusion: In all Rollover Collision all Rows are ejected from their Compartmentalization Envelope (CE) on one side of the bus. Wheelchairs users remain upside down and well secured with occupant restraints and wheelchair tiedowns in the bus that has rolled over.)

Students in School Bus Lateral Collisions are Protected by CE? In lateral collisions students opposite the collision side will be ejected from their CE in any direction that is toward the point of impact. Students on the collision side during a lateral collision will be pinned against each other and against the bus wall nearest that point of impact. At the same time students from the row across are ejected toward their fellow passengers toward the point of impact. (Conclusion: In all lateral collisions compartmentalization does not work for those students unless they are secured by a seat belt or are secured in their wheelchairs. Any person secured by a seat belt, by a three-way seat belt and shoulder harness in or out of a wheelchair may not receive protection from their Comparmentalization Envelope.)

Conclusion: The Compartmentalization Envelope for Most Students on the School Bus Is Compromised

CE as a passive student restraint system is effective only during a narrow range of collision types and intensities. Compartmentalization is not an all pervasive safety feature that exists throughout the school bus. Compartmentalization as a safety envelope requires students to be properly seated but fails to keep students safe when they are ejected out of that narrow space during a variety of collisions. Front and back bus rows, lateral collisions, rollovers, any student in a Child Safety Restraint System, a student who wears a vest anchored to the seat back—all these students may not have a CE that is required for their protection.     

References:

1. http://www-nrd.nhtsa.dot.gov/vrtc/cw/BUS_GIJune2000a.pdf dowloaded on 2/21/2007).
2. National  Association  of  State  Directors  of  Pupil  Transportation  Services,  History  of  School  Bus Safety—Why Are School Buses Built As They Are? (The Plains, Virginia: NASDPTS, 2000.
3. National Transportation Safety Board, CollisionofCSXTFreightTrainandMurrayCountySchool District  School  Bus  at  Railroad/Highway  Grade  Crossing,  Conasauga,  Tennessee,  March  28,  2000, Highway Accident Report NTSB/HAR-01/03 (Washington, DC: NTSB, 2001.
4. National Transportation Safety Board.
5. National Transportation Safety Board, SchoolBusandDumpTruckCollision,CentralBridge,New York,October 21, 1999, Highway Accident Report NTSB/HAR-00/02 (Washington, DC: NTSB, 2000).
6. NTSB, August 6, 2002.
7. Heinrich, H.W., Peterson, D., and Roos, N. (1980). Industrial Accident Prevention. New York: McGraw Hill.
8. Mollenhauer, M. (1998). Proactive Driving Safety Evaluation: An Evaluation of an Automated Traveler Information System and Investigation of Hazard Analysis Data. Unpublished Doctoral Dissertation. University of Iowa, Iowa City.
9. NHTSA Child Safety and Restraint System accessed 2/22/2007 http://www.nhtsa.dot.gov/people/injury/buses/busseatbelt/page01.htm.
10. National Transportation Safety Board, Highway Accident Report, School Bus Run-off-Bridge Accident-Omaha, Nebraska, October 13, 2001. NTSB/HAR-04/01 (Washington, DC: NTSB, 2004).
11. NTSB Omaha, NE. Pg. 14.
12. ABC World News. November 6, 2006.

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TOPIC TWO: Pedestrian Fatalities off the Bus Caused by School Bus Driver Inattention

More student pedestrians die outside the bus than on the bus. Students getting off the bus and crossing the road against traffic with the bus red lights flashing and stop sign extended are not necessarily safe. Crossing streets and roadways leads to unnecessary pedestrian deaths and injuries. Many bus drivers report one or two cars running the bus stop lights/stop sign per day. Police enforcement is not sufficient to stop these repeat offenders. State laws or local ordinances often limit the acceptance of our school bus drivers recording the vehicle type, color, license plate information that would lead to citations for stop light runners. None of the school bus construction multiple safety features apply when those students are outside the bus and on the roadways of America. On the roadway our students are more vulnerable to collisions and to injury than any pedestrian. School Bus Accident Reconstruction expert Dr. Ray Turner is prepared to assist as an accident reconstructionist and/or as an expert witness for these school bus or school-bus related fatalities or severe injuries.

TOPIC TWO Best Fix: Eliminate all bus stops requiring students to cross streets, roadways, highways, primary or secondary roads. Have the bus pull around instead and let them out on the passenger side where there is no need to cross the street. (Critics will say that to route buses in this way would be impossible. Not so. It is not that expensive. I required 165 special needs buses to NEVER let out a student to cross the roadway. In so doing our very large school district had no close-calls, accidents or fatalities for 12 years. Why can’t regular routes do the same? At least regular routes can change top 20% of the most dangerous routes where bus stop runners regularly put our students’ lives in jeopardy.

Topic Two Quick Fix #1: Challenge state legislators to facilitate school driver observation, notes, reports, photographs and witness statements as legal ground for citing school bus red light runners.

Topic Two Quick Fix #2: Require school bus drivers to record with an inexpensive one-time camera photos of red light runners.

Topic Two Quick Fix #3: Maintain a database of school bus red light runner personal and vehicle information as well as the bus stop locations where these bus stop sign runners risk our students’ lives.

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TOPIC THREE: Reducing the Severity of Student Injuries on the Bus

Most students are not injured in the vast majority of cases when other vehicles collide with the school bus. The Driver and/or passengers in the other vehicle are far more likely to be injured or killed. When colliding with a school bus most private vehicles underride the bus frame. The smaller vehicles are severely damaged through crush and passenger compartment intrusion. While this underride collision occurs in one-tenth of a second the students and driver on the bus have the advantage of a bus floor that is elevated 30 inches off the ground. The higher center of gravity and greater mass of the bus enables the students to receive far less Delta V force and less intrusion into the school bus passenger compartment. Yet private vehicles impacting a school bus in a lateral collision can cause that bus to overturn. A 90 degree rotation to the driver side shown as above is a major student occupant displacement in all thirteen row seats from front to back. Students on the driver side sitting three or two to a seat are pressed against the bus wall and window frame on their side others seated across the aisle experience a 7 foot fall. Those falling students collide with the students already pressed against the driver side wall. During some bus rollovers students are catapulted against their neighbors, or against the ceiling of the bus or against the bus wall or windows. Any of those collision surfaces in the bus are not people friendly. We have all seen a short video of a bus overturning 90 degrees to the driver side on ABCNews.com and how quickly in real time the occupant displacement occurs. None of the parents viewing such a short and dramatic video would ever want their child to be on that bus that overturned. All of us wish those students who were in the accident were not injured. The physics of an overturned bus argue otherwise. What can be done to decrease injuries with school bus rollovers?

TOPIC THREE BEST FIX: Seatbelts on school buses will reduce the occupant displacement and collision injuries occurring between students in opposite seat rows but not necessarily the collisions that can occur between seatmates when all students on the bus are secured by a seatbelt. Seatbelts in school bus accidents are considered by many in the school industry as an unnecessary and even dangerous process. We at SBAR disagree. Seatbelts reduce the level of severity of injuries for many students. Seatbelts prohibit ejections from inside the bus to outside where fatalities usually occur.

Topic Three Quick Fix #1: Meet with the school board members to require funding for new bus purchases that are seat belt equipped. Anyone who opposes you in that request should be asked: “If your child was on a bus without a seatbelt then would you also not require him or her to wear a seatbelt in your car or SUV?” Most school boards have to replace their buses every 10 or 12 years. By purchasing new buses with seat belts it would take 10 to 12 years to have the entire bus fleet so equipped. So for the parents who are genuinely concerned this solution is not a sufficient one without being in combination with other solutions.
Topic Three Quick Fix #2: School board members often avoid confrontations with concerned parents and cite their reason for avoiding seatbelt purchases on new buses and seatbelt retrofits in the existing bus fleet to the “prohibitive costs and manhours required to retrofit their existing buses.”  

Topic Three Quick Fix #3: Some board members argue: “If all school buses can’t have seatbelts then none should have them!” This is used as an excuse not to have anyone in seatbelts on any of the buses. This argument is not valid since most school board members may not know that most—if not all—of their special needs bus fleet do have seatbelts for every student, securements for every students using a wheelchair or other mobility aid, securement for every preschooler riding in a bus seat in a child safety seat. They also do not know that seatbelts have been consistently in special needs transportation for more than a quarter century.

Topic Three Quick Fix #4: The school board member may wish to quote many different leaders in the school bus industry statements as literal fact such as: “If buses are equipped with seat belts the students will not use them. If they are carefully supervised the students will use those seatbelts as weapons against other seatmates.” If this were true on special needs buses there would be very few survivors for 14 to 15 years of special needs or lift bus service when belts were used by everyone. Why would it be any different on regular buses of which 5 students or more on each 73 passenger bus are already in special education?

Topic Three Quick Fix #5: Many school board members do not realize that a large percentage of the passengers in their entire bus fleet are Pre-Ks, Kindergarteners and other very small people who weigh less than 40 pounds. They also may not be aware that any child under 40 pounds must be secured in any private vehicle or school bus with an appropriately fitted and secured child safety restraint system (CSRS). Federal Motor Vehicle Safety Standard (FMVSS) prohibits CSRS users from being secured in a non-seatbelt ready school bus seat. The same FMVSS requires that all seats that use a seatbelt or lapbelt have reinforced frames and are “seatbelt ready.” Looping seat belts around the frame of nonseatbelt ready bus seat is not only dangerous, but it is illegal. Looping seatbelts around nonreinforced seat frames does not demonstrate “due diligence” by the school board and all of its employees to violate the federal safety standards for child safety seats.

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TOPIC FOUR: Reducing the Severity of Student Injuries During a School Bus Collision - Removing or Substituting Wheelchair Trays

Students using wheelchairs ride on lift buses that are specially equipped to provide the safest ride possible. There are many different power (electric) wheelchairs on the market today that provide for the mobility needs of students on lift school buses.  Their safe bus ride requires that each student have his or her wheelchair properly secured to the floor with securement belting that is not worn, frayed or made by different manufacturers. Each belt must be properly seated in the floor tracking appropriate for that type of belt. Each securement belt must be attached to a WC-19 Standard belt loop which is located on the frame of the wheelchair to avoid contact with the wheels or any part of the frame that will come off (such as the footplates). The four-way securement of the wheelchair does not mean that the student is safe to ride on the lift bus without have occupant restraints provided as well for the student’s safe ride. Occupant restraint is a three-point body securement for the child in the wheelchair. One belt is a shoulder harness that is secured to tracking anchorage mounted above the window sill overhead from the student and behind his or her seated position. This shoulder harness connects to a two-point lap belt secured either to the bus floor or to the two rear wheelchair securement belts. Together the wheelchair securement and the occupant restraint provide seven-points of safety for the child and the mobility aid.

Yet the safety of the child who is firmly secured using these seven points is not complete until the wheelchair tray is removed during the bus ride. Many school districts with very caring and skillful driver teams (bus driver and student attendant) ignore the importance of removing the tray before the bus ride begins and returning it to the wheelchair once the student has arrived and has exited the bus by the lift platform. These Driver Teams keep the trays in place without thinking that severe abdominal injuries are possible, if not certain, during a collision when the student using a wheelchair has a tray mounted that is not soft, pliant and well-padded. Occupational Therapists in the school district can easily fit a foam-filled soft tray to be used only on the bus for each wheelchair user’s safety. Other Driver Teams have properly secured their wheelchair users and provided a foam-padded tray during the ride and forget about the danger of not securing the hard wheelchair tray so that it does not become a lethal flying object during a school bus collision. With these precautions always in place on the lift bus when collisions do occur the injury of students using wheelchairs can be minimized. Without those precautions, their injuries may be fatal.

TOPIC FOUR BEST FIX: All lift buses must use a four-way wheelchair securement integrated with occupant restraint shoulder harness and lap belts to properly secure each student using a wheelchair. All wheelchair users should either vacate their wheelchair to transfer to a school bus seat where there they can be secured using a seat belt on a seat-belt ready bus bench seat. --OR—Each student remaining in his or her wheelchair and properly secured will have a foam-padded tray to replace the hard tray used off the lift bus. –AND—Each student’s hard tray will be stored in a wall-mounted bag near the wheelchair securement area that prohibits any trays from being ejected from the bag and causing severe injuries to others during a bus frontal or rear collision, rollover or lateral collision.

Topic Four Quick Fix #1: Parents should inspect their child’s wheelchair to know exactly where the original equipment manufacturer’s (OEM) securement directions indicate each of four wheelchair securement belts must be attached to the wheelchair. Observe the same lift bus before unloading at the school loading zone to determine if the Driver Team did in fact use the appropriate securement locations and that belting for their child’s wheelchair has not come loose during the bus ride.

Topic Four Quick Fix #2: Parents should observe regularly if the Driver Team is attaching the shoulder harness and lap belts to their child. Shoulder harnesses are adjustable with a take-up band to allow for best fit across the student’s shoulders and not across the student’s face or neck. Some Driver Teams ignore the use of the occupant restraint system thinking that the wheelchair lapbelt will keep the student in the wheelchair during a school bus collision. Those wheelchair lap belts are not for collisions or displacement during sudden bus braking or sharp turning. When lift buses are carefully driven and approach a speed bump, a dip in the road or possibly override a curb during a wide turn wheelchair and seated occupants to the rear of the bus can easily be spilled from their wheelchairs or seats to the floor with severe injuries even in a very mild to moderate bus maneuver.

Topic Four Quick Fix #3: Parents should assure that the lift bus has an onboard videotape system operating on all routes for their child and that Driver Team performance with wheelchair securement, proper fitting of students using occupant restraints, removal and proper storage of wheelchair trays is being done—always--and not occasionally or when the parents or a supervisor is on board.

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TOPIC FIVE: Student Location from the Point of Impact Dictates the Amount and Types of Their Injury

The Point of Impact or Intrusion into the Passenger Compartment all interact in the dynamics of a school bus collision. From Point of Rest (POR) analyzing backward to Point of Impact then further backward to Point of Origin we at SBAR as accident reconstructionists know that student location, location, location dictates the amount of injury, injury, injury. As children we all learned to play “crack the whip.” We delighted in being at the center—or even in the middle—of the line that began to circle faster and faster.  But those children at the end of the line could not possibly run fast enough without falling, or letting go, before they fell. A comparable situation exits in a school bus when sudden and unexpected bus movements occur.
When the bus driver moves over speed bumps too fast, or hits curbs during the wide swing required to steer around residential or school zone intersections our student passengers become unseated. Buses are struck by oncoming traffic when they must encroach into the opposing traffic lane to complete their turns. Some of us can remember the “wild” ride we enjoyed in the back of the bus—even when carefully driven—that the leverage of a long bus body with thirteen rows of seats and the chassis underneath would do to unseat us and launch us into the air—often to our pleasure. Yet all these childish pleasures become nightmares when a school bus is in a collision.
Most School Bus Collisions are Compound Collision Events for Student Passengers
Collisions on the bus may occur in less than one-tenth of a second. School bus collisions, however, a rarely single event point of impact events. Most school collisions are multiple point of impact events for students on board the bus.

Frontal School Bus Collisions
A Frontal School Bus Collision places students hard against the back of the padded seat ahead of them. But what happens next while the bus is still not depleted of kinetic energy? The students then have a second collision by falling to the floor in their seat row. The fall may cause them to collide with their seatmates on the way down to the floor or on top of their seatmates already ejected to the floor. Not counting the collisions that occur within each students body (Type III Collisions), every school bus accident is at least a two-stage compound accident. Most school bus accidents have more than two-stages of collisions for students within the school bus.

Rearend Bus Collisions and Student Ejection within the Bus
Rearend bus collisions “ramp” students over their high seat backs and into the next row behind where they may collide with student seats, backpacks, books, band instruments just as the other rows of students behind them are ramped to the rear of the bus. The last row of the bus is where students are often seated in part by their own seating preference or by the driver assigning them a rear row seat. Those students seated in the last row of the seat are collided by students ramped backward against them as well as the collision point of impact at or near their rear seating area in a rear end collision. Rear end collisions are compound collisions for the student passengers involved. Students seated in the back rows are positioned in a high risk seating location. (2.19.20004 Onalaska, WI. Semi Rearends Bus with Multiple Student Injuries http://www.lacrossetribune.com/articles/2004/02/21/news/00lead.txt)

Lateral Bus Collisions without Rollovers and Student Ejection within the Bus
Lateral collisions without school bus rollovers eject students on the far side to the point of impact and into the seats of students across the aisle. On a fully loaded bus any lateral collision will launch students against other students across the aisle. The collision both for those students ejected across the aisle and for those students seated in the opposite seat row are compound collisions. All students nearest the point of impact collide with other students, with the opposite seat row bench seat, with the bus wall, with the bus window, with backpacks, books, band instruments and other student effects. Many years have passed since we were informed never to keep any object in the back window of our private vehicles since during a collision even a box of tissues or a can of soda could become a lethal weapon during a car crash. Why then should we ignore the effects of objects (students, equipment, etc.) being launched against other students on the bus during a lateral collision? Backpacks alone weight 10 to 30 pounds each while most students have then in their laps when a school bus accident occurs. That means that from 50 to 70 students—each with their own personal backpack—are launched against each other in a mix of airborne objects colliding with non-crash padded bus surfaces. Lateral bus collisions without rollovers are compound collisions for the students on board. (Brampton, Ontario. 4-11-2007. Bus Collides with Truck/Trailer and Exits into Median (No Rollover). 1 Student Fatality.)

Lateral Bus Collisions with 90 degree Rollovers and Student Ejection within the Bus
School bus 90 degree rollovers to the either side don’t just unseat students from their places. Without seatbelts on school buses those students in a quarter-turn rollover are slammed into the opposite wall against their opposite aisle seatmates, against the opposite bus wall, against the opposite bus windows and against their own seatmates and their backpacks during the ejection trajectory.  Lateral bus collisions with a 90 degree rollover is a compound collision for the student passengers on board. (Convoy, OH 2/21/2006 http://www.limaohio.com/story.php?IDnum=23782)

Lateral Bus Collisions with 1800 Rollovers and Student Ejection within the Bus
School bus 180 degree rollovers with the bus settling upside down are first a complete 90 degree as described immediately above (which in itself is a compound collision) and then adding another 90 degree rollover from a side or quarter-turn position causes students and all other objects from both sides of the aisle to fall up to seven feet into the bus ceiling. Any fall headfirst from a distance of seven (7) feet is a serious injury producing if not life-threatening fall. Since most 180 degree rollovers occur while the bus has forward momentum the students onboard and other dislodged objects will slide along the ceiling or upper side-walls toward the front of the bus. This causes students to stack up at the front of the bus against the bus firewall, the bus instrument panel, the front windows, around or on top of the bus driver and may at the same time block the front exit door from the inside because of student bodies or other objects displaced in the stepwell and against the door itself. Students who are conscious when the bus comes to rest upside down, or who become conscious soon thereafter, cannot escape from the bus through the roof hatches since they face into the ground according to the bus at its position of rest. Instead, students must attempt evacuation through side windows or dual emergency exit side windows on either side of the bus. To get to the side windows and escape from the bus requires some students to crawl over or step onto other students who may be unconscious or worse. Any attempt by students to move about or escape the bus on the slick bus ceiling surface will cause them to slip and fall and further injure themselves. An overturned school bus causes multiple or compound injuries to student occupants both prior to and following the bus point of rest?

Lift-bus 180 degree Rollovers
Lift-bus 180 degree rollovers cause further injuries to occupants than a regular bus filled with padded seats. Lift-buses have lift equipment, floor mounted wheelchair securement equipment, wall-mounted occupant restraint equipment, child safety seats, lap belts, EZ-On vests and other specialized equipment that are not secured. When dislodged in a bus collision and a rollover each of these objects exposes students ejected within the bus to contact with surfaces that are hostile to their health and safety. Occupied and secured wheelchairs allow students to remain secured to the bus floor with their head, body and arms hanging down.  When enough rescuers carefully release them they may drop from their chair to the ceiling. While students who may have withstood significant forces during the collision because they were secured with lap belts, a shoulder harness and a secured wheelchair under them may then fall through their rescuers arms and break their arms or legs. (Cotulla, TX,  Rescuers and first responders may be unaware of the slippery ceiling surface on which they are standing that will cause them to lose their footing and drop students being rescued. Securing students into backboards within the overturned lift bus does not assure that the first responders or others may successfully keep their balance and avoid their own slips, trips and falls. Any lift bus on the road has multiple objects that are not secured that become lethal objects during a rollover or a hard braking maneuver. Canes and crutches stuffed against the wall between the seat next to their owner come loose during even a mild collision and fly haphazardly across the bus injuring anyone in the way if not their owners.

Compound Collisions and Student Injuries with 270 degree or 360 degree Lift Bus Scenarios
School buses or lift buses in a collision that experience a ¾ turnover (270 degree) or a 360 degree turnover have further compound collisions and an increasing likelihood of serious injuries if ejected from their seats. The efficacy of lap belts seems obvious to anyone who considers student ejections from their seats and the increasingly complex collision scenarios during compound collisions within the bus. For student injuries due to the hostile surfaces and objects within the lift bus during a collision the danger of lift buses in rollovers (partial or complete) is much higher.

The Clothes Dryer Tumbling Effect in School Bus Rollovers

The Clothes Dryer Tumbling Effect in School Bus Rollovers

There is a “clothes dryer tumbling effect” of passengers and equipment that occurs during rollovers. With lap belts for every student in place or proper wheelchair securement and use by students of occupant restraints in their wheelchairs there remains a high risk of serious injury during rollovers within the lift bus. Multiple objects that are not properly secured or stored are ejected from their original positions and hurled about inside the lift bus. If you examine carefully most lift buses today will not present a safe and lower risk environment during a collision. You will find no storage or securement system for wheelchair trays which are not supposed to be used during the bus route service. (Refer to Laidlaw Statement 3.23.2006 Savannah, GA for student with wheelchair tray injury). How and where are the canes, crutches, long canes, walkers and other mobility aids that are stored on the lift bus? Would any or all of these objects be equally dangerous when ejected within the bus during a rollover? Backpacks on buses without lifts are equally harmful to students on board. Lift buses have both students and backpacks and mobility aids not properly secured against collision forces. (Peter C. Lapner, MD; Duong Nguyen, MD; Mervyn Letts, MD. Analysis of a school bus collision: Mechanism of injury in the unrestrained child. Canadian Journal of   Surgery, Vol. 46, No. 4, August,  2003.
http://www.cma.ca/multimedia//staticcontent/html/N0/l2/cjs/vol-46/issue-4/pdf/pg269.pdf)

Improperly Seated or Standing Students during a Bus Collision
Hard braking with airbrakes and antilock braking systems without a collision will push every regular or special needs or lift bus occupant out of their seats and against the high seat backs before falling to the floor. Sudden braking does not provide unseated students enough time to reseat themselves or brace for the ejection out of the seat without seatbelts. Seatbelted students have less movement or flexibility to assume improper seated positions than students without seatbelt use. Once ejected from their seat the unsecured students must quickly recover to regain their seats balance from their fall to the floor. While seated with legs crossed, legs underneath them, standing facing forward in their seats on their knees, facing backward on their knees in the seat, others facing toward the bus wall, others with legs extended partially out into the bus aisle all of these students can be severely injured in an otherwise minor school bus accident due to improper seating positions and dangerous falls to the bus floor.
The assumption of school bus crash safety through compartmentalization is that all students are seated with feet on the floor and their bodies facing forward and no part of their anatomy is extended into the narrow bus aisle. The public has forgotten how extensive and rigorous bus riding is for those in the back of the bus. The public and parents of students riding school buses may never know until they see a videotape of students being thrown around inside a bus during a collision before they can understand how quickly and violently students can be ejected from their seats with compartmentalization.  

TOPIC FIVE BEST FIX: Have the experts at Schoolbusaccidentreconstruction.com on your side in litigation dealing with school bus injuries. Document school bus occupant kinematics for each student on the bus and for the driver and the attendant. The more you learn in this area the more concerned you will become. You may better understand how future bus collisions and passenger injuries can be avoided or at the very least minimized. You may also begin to understand the extent to which the drivers themselves as well as their supervisors do not know what happens on all of their buses every day that does increase greatly a school district’s liability and risk. All school bus collisions should be caught on videotape to document real or false claims. School bus video data is legal documentation providing the the school district with the best defense against false accusations made by parents or others against school employees and their on-the-job and on-the-bus performance.

Topic Five Quick Fix #1: Archive videotape of all bus route activity across the entire bus fleet. Establish senior drivers and driver trainers to monitor videotapes of buses thought to be aggressive, high risk or problematic drivers. Drivers on probation or requiring retraining in safe driving techniques or proper student handling should be videotaped to show both before retraining and after retraining results. Crivers who have been reported by the public as not driving their school bus safely may be the subject of videotaping on the bus of both driver and student behavior.

Topic Five Quick Fix #2: Go digital! Convert from all existing videotape archived to digital (hard drive) storage for quick access of all buses, spot checks, looking for red flag bus events and monitoring reported violators. Store the digitized video route records over the course of a year. A tetrabyte hard drive (1,000 Gigabytes) costs school districts $350 to $400 each and can store more than a full year of videotape for every bus in an entire fleet.

Topic Five Quick Fix #3: Purchase a tetrabyte hard drive storage system for each school year to archive driver and student behaviors on the bus for up to seven years (statute of limitations). When date and time stamped with bus number shown on the data source this visual and auditory information is the best possible defense against false accusations made and litigation brought against school districts and drivers who are proven to be doing a good job on the bus. Could you prove today what went on October 13, 2003 on bus 404 and 7:37 AM? Student behavior documentation also reveals an objective bus ridership log if all the faces of the students riding can be recognized from the camera angles.

Topic Five Quick Fix #4:Set up CD (charged coupled device) –based digital monitors front looking back, back looking front and mid-bus looking both ways in a digital format. This provides a much wider view for the supervisor or digital storage monitor than the driver can gain and still safely drive the bus. Good bus drivers do not complain about being videotaped at any and all times. Questionable drivers will quit their job when they know that they are being observed and their inappropriate driving is being fully documented. The end result is a safer fleet, safer drivers and especially safer students.

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