Highway Accident Report

Adopted: August 14, 1975
U.S. ROUTE 395,
JUNE 29, 1974

NTSB Number: HAR-75/05
NTIS Number: PB-245737/AS

This report describes and analyzes an accident involving a tractor-semitrailer, loaded with lumber, that experienced loss of braking capability while descending Sherwin Pass, a steep, long grade located along U. S. Route 395. The unit suddenly began to accelerate at a point 5 to 5 1/2- miles from a truck parking area where the driver had stopped to adjust his brakes. It managed to remain on the roadway for an additional 2 to 2 1/2 miles, but, as it was attempting to negotiate a curve, the trailer separated from the tractor and overturned in front of a pickup/camper/trailer traveling in the opposite direction. All seven occupants of the pickup, which burst into flames at impact, died in the accident.

The National Transportation Safety Board determines that the probable cause of this accident was the loss of braking which permitted the tractor-semitrailer to run away. The loss of braking effectiveness was caused by the improper adjustment of the brakes by the driver, the selection of too high a gear or descent, and a weight overload of the truck.
This report contains recommendations to the Federal Highway Administration.


The National Transportation Safety Board recommends that the Federal Highway Administration:

1. Develop and disseminate throughout the motor carrier industry, an "On Guard" bulletin alerting drivers of commercial vehicles equipped with externally adjustable braking systems of:

a) The need to be familiar with company policies and practices with respect to on-road adjustment of brakes;

b) methods and techniques for detecting potential or existing problems in adjustment;

c) the scope of the problem in insuring proper brake adjustment;

d) methods and techniques for the proper on-road adjustment of braking systems currently and generally in use. (Recommendation H-75-17)

2. In cooperation with the motor carrier industry and driver organizations, determine what critical roadway characteristics information should be available, especially to drivers of commercial or other large vehicles, to assure their safe descent of long/steep highway grades. (Recommendation H-75-18)

3. Review the existing application of signing configurations for long/steep highway grades in each State in order to identify problem areas and to obtain information for developing more adequate signing standards for various highway grades. (Recommendation H-75-19)

4. Establish, in its adopted Manual of Uniform Traffic Control Devices for Streets and Highways, provisions which require the presentation of critical roadway characteristic information to drivers of commercial or other large vehicles at long/steep grades, and insure application of these provisions through the authority contained within Highway Safety Program Standard 13, Traffic Engineering Services. (Recommendation H-75-20)

5. Establish a design policy for long/ steep grades that will insure the provision of escape routes when the character of the grade has a potential for contributing to the generation of runaway vehicles. (Recommendation H-75-21)