Highway Accident Summary Report - Truck Loss of Braking Control on Steep Downgrade and Vehicle Collision

Plymouth Meeting, Pennsylvania
April 25, 1996

NTSB Number: HAR-97-02-SUM
NTIS Number: PB97-916202
Adopted October 17, 1997
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Abstract

On April 25, 1996, a truck with a concrete mixer body, unable to stop, proceeded through an intersection and collided with and overrode a passenger car near Plymouth Meeting, Pennsylvania. The driver of the car was fatally injured, and the truckdriver sustained minor injuries.

The major safety issues discussed in this report are the maintenance and truck inspection practices of JDM Materials Company, Inc., and the adequacy of Federal and State guidelines for conducting truck air brake system inspections.

Probable Cause

The National Transportation Safety Board determines that the probable cause of this accident was the improper maintenance of the accident truck by the JDM Materials Company, Inc., the fracture of the drain valve, and the inoperative low-air-pressure warning switch, which resulted in the driver's loss of braking control. Contributing to the accident was the lack of Federal and State inspection procedures for commercial vehicles with dual air brake systems that can detect either reversed air brake lines or inoperative low-air-pressure warning switches.

As a result of its investigation, the Safety Board issued recommendations to the Federal Highway Administration; the Commercial Vehicle Safety Alliance; the American Trucking Associations, Inc.; the National Ready Mix Concrete Association; the JDM Materials Company, Inc.; the Pennsylvania Department of Transportation; the Truck Manufacturers Association; the National Highway Traffic Safety Administration; and the Society of Automotive Engineers.

Recommendations

As a result of its investigation of this accident the National Transportation Safety Board makes the following safety recommendations:

To the Federal Highway Administration:

In cooperation with the Commercial Vehicle Safety Alliance, develop an inspection protocol that could be easily administered by inspection personnel for detecting either reversed air brake lines or inoperative low-air-pressure warning switches on commercial vehicles equipped with dual air brake systems. (H-97-31)

To the Commercial Vehicle Safety Alliance:

In cooperation with the Federal Highway Administration, develop an inspection protocol that could be easily administered by inspection personnel for detecting either reversed air brake lines or inoperative low-air-pressure warning switches on commercial vehicles equipped with dual air brake systems. (H-97-32)

To the American Trucking Associations, Inc.:

Notify your members through sources, such as the Transport Topics magazine, of the facts and circumstances of this accident and, in cooperation with the American Trucking Associations' Maintenance Council, urge your membership to implement procedures that will ensure that air brake manufacturers' suggested installation, inspection, and functional test procedures are adhered to during and after maintenance on truck air brake systems. (H-97-33)

To the National Ready Mix Concrete Association:

Notify your membership through sources, such as your Dispatcher newsletter, of the circumstances of this accident and urge them to implement procedures that will ensure that air brake manufacturers' suggested installation, inspection, and functional test procedures are adhered to during and after routine maintenance on truck air brake systems. (H-97-34)

To JDM Materials Company, Inc.:

Implement procedures that will ensure that air brake manufacturers' suggested installation, inspection, and functional test procedures are adhered to by company mechanics performing maintenance on the company's truck brake systems. (H-97-35)

To Pennsylvania Department of Transportation:

Develop an easily administered inspection protocol for detecting reversed air lines and inoperative low-air-pressure warning switches on dual air brake system vehicles. (H-97-36)

To the Truck Manufacturers Association:

Notify your membership of the circumstances of this accident and urge them to install, on all the commercial trucks they manufacture with dual air brake systems, separate low-air-pressure warning devices that will independently alert operators to a loss of air pressure in either system. (H-97-37)

To the National Highway Traffic Safety Administration:

In cooperation with the Society of Automotive Engineers, develop specifications and requirements for the installation, in heavy trucks with a dual air brake system, of separate low-air-pressure warning devices that will independently alert drivers to a loss of air pressure in either system. (H-97-38)

To the Society of Automotive Engineers:

In cooperation with the National Highway Traffic Safety Administration, develop specifications and requirements for the installation, in heavy trucks with a dual air brake system, of separate low-air-pressure warning devices that will independently alert drivers to a loss of air pressure in either system. (H-97-39)