Skip Ribbon Commands
Skip to main content
Animations for Highway Special Investigation report, September 21, 1999
Bookmark and Share this page

 

Event Add On

Animations for Highway Special Investigation report, September 21, 1999
 
 

Highway Special Investigation Report - Bus Crashworthiness

NTSB Number: SIR-99-04
NTIS Number: PB99-917006
Adopted September 21, 1999
PDF

Animations

Disclaimer: Simulations presented below used scene and geological surveys, highway design plans, witness statements, vehicle testing, vehicle plans and vehicle operating characteristics. The depictions represent actual lighting and weather conditions at the time of the accident

Two animated views of the vehicle dynamics of each accident are shown and several views of occupant kinematics unrestrained and restrained with lap belts and lap belts and shoulder belts are also shown. Slides showing the predicted injuries and accident vehicles are also presented. The schoolbus accidents are:

1) Monticello, Minnesota, April 10, 1997

photo of school bus.Accident Vehicle

 

 

Crash
Overhead zoom view of the bus and truck approaching the intersection and the crash.This view displays the approach of both vehicles to the intersection, the crash and the vehicles' trajectory after impact. The truck is approaching the intersection at 55 mph, slows to 53 mph, brakes and slows to about 49 mph at impact. The truck goes past a "STOP" sign. The bus accelerates from 46 to 50 mph at impact.

overhead view of intersection.Slow
Monticello, MN - Overhead Slow motion view of the bus and truck crash. This view displays the crash and the vehicles' initial trajectory after impact. The truck is traveling at 49 mph at impact. The bus accelerates to 50 mph at impact.

 

overhead view of bus interior.Monticello_unrest.rm (Video = 486K)
Overhead view of the unrestrained occupant kinematics (1/10th speed). This view displays the occupant kinematics for the six occupants located in the last three rows of the school bus. Head injuries were predicted for the three occupants initially seated along the driver's sidewall.

Monticello2pb_ind.rm (Video = 271K)
Monticello, MN - Overhead view of the lap belt restrained occupant kinematics (1/10th speed). This view displays the lap belted occupant kinematics for the six occupants located in the last three rows of the school bus. Head injuries were predicted for four of the simulated occupants.

Monticello3pb_ind.rm (Video = 280K)
Monticello, MN - Overhead view of the lap/shoulder belt restrained occupant kinematics (1/10th speed). This view displays the lap/shoulder belted occupant kinematics for the six occupants located in the last three rows of the school bus. Head injuries were predicted for five of the simulated occupants.

injury chart.Predicted Head Injuries
This slide illustrates the predicted head injuries in the Monticello, MN simulation for each of the three restraint conditions: unrestrained, lap belt restrained, and lap/shoulder belt restrained. The yellow X indicates the occupant predicted to sustain a head injury. Three head injuries were predicted for the unrestrained occupants, four for the lap belt restrained occupants and five for the lap/shoulder belt restrained occupants.

injury chart.Predicted Chest Injuries
This slide illustrates the predicted chest injuries in the Monticello, MN simulation for each of the three restraint conditions: unrestrained, lap belt restrained, and lap/shoulder belt restrained. The yellow X indicates the occupant predicted to sustain a chest injury. Four chest injuries were predicted for the unrestrained occupants, four for the lap belt restrained occupants and three for the lap/shoulder belt restrained occupants.

injury  chart.Predicted Neck Injuries
This slide illustrates the predicted neck injuries in the Monticello, MN simulation for each of the three restraint conditions: unrestrained, lap belt restrained, and lap/shoulder belt restrained. The yellow X indicates the occupant predicted to sustain a neck injury. Neck injuries were not investigated for the unrestrained occupants because the appropriate simulated dummy was not available at the time. Three neck injuries were predicted for the lap belt restrained occupants and two for the lap/shoulder belt restrained occupants.

2) Holyoke, Colorado, September 1, 1998

bus crash photo.Accident Vechicle

 

 

Chase
Overhead Chase view of the truck as it approaches the schoolbus from behind. This view displays the truck as it approaches the stopped bus that begins to accelerate. The truck is travelling 60 mph, brakes and slows to 50 mph at impact as it turns left. The stopped bus accelerates to about 5 mph.

Front
View from in front of the crash as the truck hits the bus. This view displays the crash from in front of the bus as the truck strikes the bus, the bus spins and rolls over.

 

Holyoke_standing.rm (532K)
Overhead view of the unrestrained occupant kinematics (1/10th speed) with the two ejected occupants standing in the aisle. This view displays the occupant kinematics for the four occupants located in the last two rows of the school bus. Passenger reports were unclear whether the two ejected passengers were seated at the time of impact. Many simulations were performed to look at the potential ejection paths and to replicate the final rest positions of these two occupants. Head injuries were predicted for the two ejected occupants.

Holyoke_unrest.rm (486K)
Overhead view of the unrestrained occupant kinematics (1/10th speed) with the two ejected occupants seated. This view displays the occupant kinematics for the four occupants located in the last two rows of the school bus. Passenger reports were unclear whether the two ejected passengers were seated at the time of impact. This simulation shows all occupants seated within the compartment. A single head injury was predicted as one occupant's head contacted the sidewall during the overturn sequence.

Holyoke2pb_ind.rm (545k)
Overhead view of the lap belt restrained occupant kinematics (1/10th speed). This view shows the lap belt restrained occupant kinematics for the four occupants located in the last two rows of the bus. Head injuries were not predicted for these simulated occupants.

Holyoke3pb_ind.rm (538k)
Overhead view of the lap/shoulder belt restrained occupant kinematic (1/10th speed). This view shows the lap/shoulder belt restrained occupant kinematics for the four occupants located in the last two rows of the bus. Head injuries were not predicted for these simulated occupants.

Predicted Head Injuries
This slide illustrates the predicted head injuries in the Holyoke, CO simulation for the unrestrained condition with the two ejected occupants standing in the aisle. The yellow X indicates the occupant predicted to sustain a head injury. Three head injuries were predicted for the unrestrained occupants. Two head injuries were predicted for the ejected occupants while the final head injury was predicted when the occupant on the opposite side interacted with the two ejected occupants. When seated within the seating compartment either restrained or not restrained, the occupants were not ejected and the predicted injuries were reduced. Chest and neck injuries were also investigated but were not presented graphically.

3) Holmdel, New Jersey, September 18, 1998

Accident Vehicle

 

 

Bus Chase
Chase View from behind the bus as the bus approaches the intersection and crashes. The speed of the bus is 22 mph as it approaches the intersection and it slows to 21 mph at impact. The speed of the truck on the approach was 41 mph and it slowed to about 39 mph at impact with the bus.

Dynamics View
A close-up view of the Holmdel crash and the vehicle dynamics. This view shows the impact, bus deformation, vehicle separation, overturn of the truck onto the bus and a portion of the vehicles' slide to their final resting positions.

overhead view of bus interior.Sideways
Holmdel, NJ - Overhead view of the unrestrained occupant kinematics (1/20th speed). This view shows the unrestrained occupant kinematics for the four occupants located in the first two rows of the bus. The occupant in seat 1A is positioned sideways, representing the passenger's statements. A head injury was predicted for the occupant in the upper right side of the video corresponding to the actual head injury sustained by that bus passenger.

overhead view of bus interior.Forward20
Overhead view of the unrestrained occupant kinematics (1/20th speed). This view shows the unrestrained occupant kinematics for the four occupants located in the first two rows of the bus. The occupant in seat 1A is positioned forward to enable comparisons to the restrained conditions. Two head injuries were predicted for the occupants in the first row of seats.

overhead view of bus interior.2pb
Overhead view of the lap belt restrained occupant kinematics (1/20th speed). This view shows the lap belt restrained occupant kinematics for the four occupants located in the first two rows of the bus. Head injuries were predicted for all four occupants.

overhead view of bus interior.3pb
Overhead view of the lap/shoulder belt restrained occupant kinematics (1/20th speed). This view shows the lap/shoulder belt restrained occupant kinematics for the four occupants located in the first two rows of the bus. Head injuries were predicted for the two occupants seated along the driver's side (left side on the video).

injury chartPredicted Head Injuries
This slide illustrates the predicted head injuries in the Holmdel, NJ simulation for each of the three restraint conditions: unrestrained, lap belt restrained, and lap/shoulder belt restrained. The yellow X indicates the occupant predicted to sustain a head injury. One head injury was predicted for the unrestrained occupants, four for the lap belt restrained occupants and two for the lap/shoulder belt restrained occupants. Chest and neck injuries were also investigated but were not presented graphically.

4) Other Accidents

Flagstaff, AZ

 

 

Easton, MD

 

 

Buffalo, MT

 

 

The simulations were produced on an HVE™ system using m-smac (McHenry Software,Inc.), ReadDataFiles and GATB (Collision Engineering Associates, Inc.), MADYMO (developed in conjunction with a NHTSA contractor), EDSMAC™ EDVDS™, EDVSM™ and EDGEN™ programs. All of the programs starting with "ED"; are trademarks of the Engineering Dynamics Corporation.


 


 

Enter the YouTube ID of each video separated by a semi-colon (;). Example: "LV5_xj_yuhs; QgaTQ5-XfMM; VWW8DMpfI9U; BgAlQuqzl8o;"

lCOxE9in3pI; 0mTuubfAnCA; Vip4AKEH9SQ; P85mRQltPfE; WncHtoooUnE; fBjNV0z4yu8; Jl32_rVj3ig; 6r4HCQPmDBI; NNES0nFfML8; z0rHT_FKf5U

Related Information

Related Press Releases

Related Reports

Related Events

Related Investigations