HIGHWAY ACCIDENT REPORT
Adopted: May 24, 1973
PROPANE TRACTOR- SEMITRAILER
OVERTURN AND FIRE
U.S. ROUTE 501,
LYNCHBURG, VIRGINIA
March 9, 1972 
NTSB Number: HAR-73/03
NTIS Number: PB-221986 
SYNOPSIS
At 2:30 p.m. on March 9, 1972, a tractor-semitrailer (tank) carrying liquid propane under pressure was traveling north on U.S. Route 501 at approximately 25 m.p.h. At a point 7.1 miles north of Lynchburg, Va., the truck, while changing lanes in a 48 degree curve to the left on a 6.9 percent downgrade, overturned onto the right shoulder of the road. The truck slid along the shoulder on its right side and struck a rock outcropping, which ruptured the tank and permitted the liquid propane to escape. On exposure to the atmosphere, the propane vaporized into a cloud, which spread rapidly throughout the area. Within 1 or 2 minutes a fire erupted in the propane-air mixture.

The truckdriver, apparently not injured in the rollover, fled on foot north from the overturned vehicle. When the propane-air mixture ignited, the truckdriver was enveloped in the fire and was killed. Two southbound motorists, who had stopped their cars north of the overturned truck, and a passenger of one of the motorists were severely burned when the vapor cloud ignited.
The occupants of a house located in a hollow below and west of the highway heard the crash and ran from the house, but were caught in the propane-air vapor flash and were severely burned. One of these victims died as a result of his burns. The house, outbuildings, and about 12 acres of woodland were destroyed in the ensuing fire.

The National Transportation Safety Board determines that the cause of the overturn was the driving of the tractor-semitrailer on the wrong side of the road, and a subsequent evasive steering action which exceeded the limited capability of the truck to resist overturn. Contributing factors included a misleading traffic control sign, an inadequate road-marking system, and the high center of gravity of the truck. The causes of the burn fatalities and injuries were rupture of the tank at a point susceptible to rupture and the inadequacy of the required placards as a means of warning bystanders of the nature and range of the hazard.

RECOMMENDATIONS

The National Transportation Safety Board recommends that:

1. The Hazardous Materials Regulations Board of the Department of Transportation and the Tank Truck Technical Council consider mail a copy of the written route plan to the desirability of amending 49 CFR 178.337-6 (Closure for manhole) to require that all manhole assemblies in MC 331 pressure vessels manufactured after a specified date be located in the upper quadrant of the rear hemispherical head to minimize the possibility of manhole-assembly collision with other vehicles or objects. (Recommendation No. H-73-20)

2. The Office of Hazardous Materials study the warning system deficiencies demonstrated in this accident. The proposal for a Hazardous Material Information System issued by OHM on June 6, 1972 should be carefully reviewed to insure that warnings of impending danger and advice are given in an understandable manner to the general public as well as to emergency personnel. The capability of the system to warn those at a distance should be equal to the range of the hazard and should not rely on the physical condition of the driver. The system should function under all weather conditions and the range of warning should be specified by regulation. (Recommendation No. H-73-21) This recommendation was previously published in the Board's report NTSB-HAR-72-5, Automobile /Truck Collision Followed by Fire and Explosion of Dynamite Cargo, U.S. Highway 78 near Waco, Georgia, on June 4, 1971.

3. The Bureau of Motor Carrier Safety (Federal Highway Administration) revise the Motor Carrier Safety Regulation contained in 49 CFR 397.9 as follows:

a. Part (a) be revised to require the safest feasible route with strict compliance by the driver;

b. Part (b) be revised to include, in addition to Class A and Class B explosives, all bulk hazardous materials that can disperse or react with violent, abrupt, incapacitating or lethal effects; and to require that a driver preparing a written route plan when he begins a trip at a location other than the carrier's terminal, mail a copy of the written route plan to the carrier before departure. (Recommendation No. H-73-22)

4. The National Highway Traffic Safety Administration expedite its proposed rulemaking on Highway Safety Standard No. 5 (Driver licensing), and expand the standard to require that each State, before issuing a new or renewal driver's license, check with the National Driver Register to determine whether the applicant's right to drive is under suspension or revocation in any jurisdiction. (Recommendation No. H-73-23)

5. The Bureau of Motor Carrier Safety (Federal Highway Administration), in cooperation with the Tank Truck Technical Council, investigate the overturn stability problem created by liquid cargo surging in tank-truck combinations. The ultimate objective of such an investigation should be the promulgation of Federal regulations to specifically limit the effects of surge. (Recommendation No. H-73-24)

6. The National Highway Traffic Safety Administration modify the work statement of the National Driver Register study being conducted by the Safety Management Institute, to assure that specific consideration is given to the accessibility to the Register by employers or prospective employers of persons who are required, as a condition of employment or retention, to possess a valid motor-vehicle driver's license. (Recommendation No. H-73-25)

7. The Federal Highway Administration (FHWA) review the policies of the Commonwealth of Virginia relative to compliance with the standards in the FHWA Manual on Uniform Traffic Control Devices which concern the signing and marking of highways in mountainous areas. (Recommendation No. H-73-26)

8. The Commonwealth of Virginia review its policies of signing and marking highways in mountainous areas for conformity with the FHWA Manual on Uniform Traffic Control Devices. (Recommendation No. H-73-27)

9. The National Highway Traffic Safety Administration amend its proposed revision of Highway Safety Program Standard No. 5, Driver Licensing, to add the provisions of Chapter 6, Article I, Section 6-106(c) of the Uniform Vehicle Code, Revised 1968, and require that whenever an application is received from a person previously licensed in another jurisdiction, a copy of such driver's record be obtained from such other jurisdiction, thus determining, before issuing or renewing any motor vehicle driver's license, if the applicant had an accident or traffic-violation record which might preclude the issuance of a motor vehicle driver's license in the inquiring State. (Recommendation No. H-73-28)

10. The several States adopt and fully implement the provisions of Chapter 6, Article I, Section 6-101 (c) of the Uniform Vehicle Code, Revised 1968, which sets forth the "done license concept" of driver licensing, to assure that each licensed motor-vehicle driver holds only one valid driver's license. (Recommendation No. H-73-29)