conasauga, tennessee railroad/highway grade … · •dynamic camera view trailing school bus ......
TRANSCRIPT
Toxicology Testing
• Bus driver tested post-accidentRequired by Federal law
Negative for alcohol and illicit drugs
Positive for substances common in over-the-counter medications
• Train crew tested post-accidentNot required by Federal law
Negative for alcohol and illicit drugs
Vehicle Simulation
• Developed based on the physical evidence andonboard recording devicesBus speed based on onboard video recorderTrain speed based on event data recorderVehicle damage patternsFinal rest locations
• Characterizes the best fit to physical evidence• Representative of the accident sequence but
doesnot show the actual accident
Simulation Videos
• Dynamic camera view trailing schoolbus
• Static camera view detailing collisionand motion to final rest
• School bus driver’s potential view
• Train engineer’s potential view
Vehicle Simulation Summary
• School bus speed at impact was about15 mph
• Train speed at impact was about 51mph
• Peak school bus accelerations:30 Gs lateral acceleration
2500 deg/second rotational acceleration
• Peak train deceleration: less than 2 Gs
Vehicle Simulation Summary, Cont.
• Train was potentially visible for about 2seconds from the school bus driver’sside window
• School bus was potentially visible formore than 4.6 seconds prior to impact
Issues
• Driver performance
• Passive grade crossing safety
• School district oversight
• Grade crossing databases
• Audibility
• Survival factors and occupantkinematics
• Intelligent transportation systems
Parties
• National Highway Traffic Safety Administration
• Federal Motor Carrier Safety Administration
• Federal Railroad Administration
• Tennessee Highway Patrol
• Polk County District Attorney’s Office
• Murray County, Georgia, School District
• CSX Transportation
Grade Crossing Safety
• School bus drivers required to stopbefore crossing railroad tracks
• Driver stated she followed properprocedures
• Analysis of videotapes on bus indicatedshe did not stop
• Driver did not stop on at least eightprevious occasions
Murray County SchoolDistrict
• 74 buses
• 54 full-time busdrivers
• 7 substitute drivers
• Annual mandatory training
• Operation Lifesaver classes
Murray County SchoolDistrict Routing
• Grade crossings
18 in the school district
15 crossed by school buses
Does not include accident crossing
• Changes in routing
School Bus Routing
• Recommended practicesNHTSA’s Guideline 17
NASDPTS’ National SchoolTransportation Specifications andProcedures
Annually plan and review school busroutes for hazards
• Murray County School Districtpractice: no hazard identification
Murray County SchoolDistrict Oversight
• NASDPTS’ National SchoolTransportation Specifications andProcedures• Bus Drivers Manual: Procedures andRules• No documentation of performanceevaluations
Fox River Grove, IllinoisRecommendations
• To NASDPTS:Encourage members to develop program
for identification of school bus routehazards and
Encourage members to routinely monitorand evaluate all bus drivers (H-96-52)
• To NASDPTS:Consider railroad/highway grade crossings
when establishing routes (H-96-53)
Carrsville, VirginiaRecommendation
• To the States:
Encourage local school districts toestablish and enforce procedures tomonitor driver compliance (H-85-4)
School Bus Routing andDriver Evaluation
• Prior to accidentDriver failed to stop at crossing
School district did not monitor drivers
School district missed opportunity to identifyproblem
School district did not identify route hazards
• Post-accidentRoute hazard recognition program
Driver evaluation program
Federal Railroad AdministrationGrade Crossing Inventory
• Maintained by the FRA
• Includes data from two sources:
Grade Crossing Inventory (includes datafrom 1974 to latest records)
Accident history (includes data from 1975to latest records)
Grade Crossing Inventory
• Inventory files provided voluntarily• Erroneous and noncurrent data willalter accident prediction values• FRA does not have authority torequire States or railroads to updateinformation• Data from inventory needs to beaccurate
FRA’s Web-based AccidentPrediction System
• Ranks crossings by predicting numberof collisions per year• Raises awareness of potential danger athighway grade crossings• Used in combination with other site-specific information in makingdecisions about crossing improvements
FRA’s Web-based AccidentPrediction System
• Uses information about crossings’physical and operational characteristicsfrom Grade Crossing Inventory• Uses 5 years of crossings’ accidenthistory
FRA’s Web-based AccidentPrediction System
• Helps school bus route planners becomefamiliar with factors that affect crossingsafety• Helps route planners make decisionsabout school bus routing
School Bus Use and StateHazard Indexes
• Some States factor in school bus use• Crossings may be upgraded morequickly if school bus use is part ofhazard index
Audibility
• Driver required:Stop the bus
Open loading door and driver’s window
Turn off radio and listen
Look both ways
Proceed when clear
• Student did not hear train horn
• Driver did not turn off radio and opendoor or window
Testing
• Bus stopped, radio on, door closed:horn 4 decibels above ambient• 10 decibels required for sound to reachalerting level• Bus stopped, radio off, door open: horn25 decibels above ambient
Speaker Placement
• Safety Board has maderecommendations discouraging radiospeaker placement near the driver• Georgia informed local school districts• Speakers still placed near the driver
Survival Factors Issues
• School bus driver seat belt systemanchor point locations• School bus sidewall and seat frameexemption from Federal Motor VehicleSafety Standard (FMVSS) 222
School Bus Driver Belt System
• Driver had been beltedand was ejected• Driver belt systemanchor points spannedseparated vehiclecomponents• Webbing failureoccurred• Potential for serious orfatal injury
Survival Factors
• FMVSS exemptionsInterior sidewalls
Other interior structures
• Serious or fatal injury to passengers inlateral collision; striking nonenergy-absorbing surfaces
• Focus on injury causation for passengersnot directly in impact area
Passenger Injuries in FrontPortion of School Bus
• Two front-row unbelted passengerswere seriously injured and ejected; theyimpacted sidewalls and interiorstructures• Second-row belted passenger notejected; only passenger to sustain minorinjury
• Passenger Injuries in MiddlePortion of School Bus• Two unbeltedpassengers on rightside were in area ofdirect impact andsustained fatalinjuries• One unbeltedpassenger on left sidewas propelled intoarea of intrusion andseriously injured
Passenger Injuries in RearPortion of School Bus
• One unbelted passenger on left side inlast row was outside impact area• Propelled out of seat compartmentacross bus width and struck rightsidewall• Fatally injured
Serious and Fatal InjuryCausation
• Passenger movement out of seat compartment• Ejection• Impact forces from collision• Intrusion from locomotive into bus• Impact into nonenergy-absorbing bus interiorsurfaces
Occupant Simulations
• Developed based on crash pulse fromvehicle dynamics simulation• Known initial seating positions based ononboard video recorder• Linear contusion pattern on passengerseated in back of bus• Representative of occupant motion but doesnot show actual motion; valid forcomparisons
Simulations
• Actual restraint conditions: all unrestrainedexcept occupant in second row who wasrestrained with lap belt• All occupants unrestrained• All occupants lap belt-restrained• All occupants lap/shoulder belt-restrained
Occupant SimulationSummary
• Rear of bus:
High lateral and angular accelerations
Restraints not beneficial
• Front of bus:
Properly fitted restraints beneficial
When unbelted, occupants struck interiorsurfaces and were ejected
Board has investigated numerousaccidents with passengers propelled outof seating compartments and injured
Board has also found passengers whoremained within seating compartmentssustained serious and fatal injuries fromstriking nonenergy-absorbing interiorsurfaces in lateral impacts
FMVSS 222
• Purpose: to reducedeath and injuryseverity that resultfrom impact of busoccupants againststructures withinvehicle duringcrashes anddriving maneuvers• Exempted:sidewall, window,and door structures
In-Vehicle Warning Systems
• Alerts driver to oncoming train
• Minnesota and Illinois testing
• Previous recommendation
• DOT response
Not specific on guiding implementation
No further responses
No additional plans for testing
Emergency Response
• Passerby and train crew reportedaccident• No delay in emergency response• Rural area• Driver incapacitated
Automatic CollisionNotification
• ACN alerts authorities to collision
Detects crash
Transmits information to local 911 center
• Reduces notification time, particularlyin rural areas
From 9 minutes to 1 minute
Could save 3,000 lives per year