An Indianapolis tanker truck accident has prompted both an investigation and policy review by the National Transportation Safety Board. The NTSB is considering whether commercial trucks generally, but particularly tanker trucks that carry liquid hazardous materials, should be required to have electronic stability control systems to prevent rollover accidents.
The truck accident that prompted a two-day hearing on the subject occurred on October 22 of last year. An International truck tractor hauling a 11,600- gallon cargo tank semi-trailer carrying liquefied petroleum gas (propane) along I-69 in Indianapolis struck a bridge guardrail, rolled over, and slid into the bridge abutment and pillar of an intersecting overpass on I-465.
The trailer, filled with propane, pulled free of the tractor part of the truck, rolled on its side and caught fire. A breach in the trailer allowed the liquefied petroleum gas to escape, vaporize and ignite, resulting in a fireball that could be seen for miles. Eight other vehicles caught fire — one at such a high temperature that its fenders were melted off the car.
The tanker’s driver and four others were injured in the catastrophic truck accident. I-465 was closed for more than a day.
NTSB Considers How to Reduce Rollover Truck Accidents
The two-day public hearing was held on August 3rd and 4th in Washington, D.C. with the goal of considering a range of safety issues and strategies that could help reduce the incidence of commercial truck accidents generally and of cargo tanker rollovers in particular.
Nationwide, there is an average of 1,265 tanker truck rollovers. According to the NTSB, driver error is accounts for 78 percent of those accidents, but semi-trucks’ high centers of gravity and their lack of electronic stability systems may be significant causes as well.
One of the issues the NTSB considered during the meeting is whether electronic stability control systems similar to those required for all new cars could prevent tanker rollover accidents. In an electronic stability control system, sensors tell the vehicle’s computer when the vehicle’s or cargo’s weight is shifting. The computer then automatically applies brakes to one or more wheels to compensate.
Federal law requires all new cars to have the systems, but federal trucking regulations have not required them on semi trucks. Rollover prevention technology is more expensive to implement on commercial trucks than on passenger cars, and it is generally considered impractical to retrofit all existing tractor-trailers with the technology.
“This technology is somewhat more expensive,” admits Henry Jasny, general counsel for the nonprofit Advocates for Highway and Auto Safety, “but that it wouldn’t be required for trucks when they are so over-represented in crashes doesn’t make sense to us.”
In addition to the question of mandating rollover prevention systems, the group of truck accident investigators, highway safety engineers and trucking industry representatives discussed:
• Crashworthiness standards for cargo tanks transporting high-risk hazardous materials
• Vehicle design changes to lower their centers of gravity
• Improving driver training and testing
• Roadway factors, such as shoulder grade, that contribute to vehicle instability
• Initiatives to protect highway bridge piers from vehicle impacts
Related Resources:
• “NTSB releases new information in advance of public hearing on the rollover and fire of a cargo tank vehicle in Indianapolis, Indiana” (NTSB Press Advisory, July 30, 2010)
• “NTSB probes rollovers by hazmat tanker trucks” (Associated Press, August 3, 2010)