NTSB Number: HSS-72/04
NTIS Number: PB-214743 

One of the most significant fog-related accidents investigated by the Safety Board was the series of multiple-vehicle collisions followed by fire which occurred on the New Jersey Turnpike under conditions of fog in November 1969. A public hearing was held to determine the probable cause of this accident. At that time, it was not possible to deal with all the aspects of highway fog that related to the accident. Consequently, a symposium on the subject of highway fog was conducted by the National Transportation Safety Board in August 1971.
This study is the culmination of what the Safety Board has learned through its accident investigations, the public hearing dealing with the New Jersey Turnpike accident, fog symposium, and review of pertinent research studies and literature.

The study reviews the various approaches that have been taken to prevent fog accidents or that have a bearing on the problem; namely, driver education, fog detection and guidance systems, environmental control, highway department procedures, vehicle and. highway lighting, enforcement, and post accident control.

At present, there are some classes of highway fog for which there is no established solution that will allow an Interstate highway to operate efficiently. In this regard, the present application of basic speed rule as a safety control should be reassessed.
The study includes recommendations intended to allevaiet the highway fog problem from several directions.

A. Fog Accidents Investigated by the National Transportation Safety Board
In its investigation of a number of major fog-related highway accidents, the National Transportation Safety Board has become aware of unresolved problems dealing with highway fog, especially on the newer high-speed limited-access highways.

RECOMMENDATIONS

The National Transportation Safety Board recommends that:

The Federal Highway Administration and the American Association of State Highway Offiials, in cooperation with

various State highway departments, particularly in those States subject to heavy fog, develop standards and procedures for controlling highway traffic on the interstate and high-speed highways during heavy fog or other visibilitylimiting conditions, which would: (a) close down temporarily to all vehicular traffic that segment of the highway experiencing fog; or (b) to close down temporarily to all heavy-duty trucks access to, those segments of the highway under adverse visibility conditions. (Recommendation H-72-49)

The Federal Highway Administration expedite its short- and long-range program to develop highway guidance systems that provide drivers with information about the status (ie., speed) of vehicle operation ahead. (Recommendation No. H-72-50)

The National Highway Traffic Safety Administration assume a leadership role with driver educators to resolve the conflicting information which is being taught relative to driving tactics in fog. (Recommendation No. H-72-51)

The National Highway Traffic Safety Administration modify the Driver Education Standard (Standard No. 4) to include more definitive information relative to reduced-visibility driving. (Recommendation No. H-72-52)

John H. Reed, chairman, filed the attached concurring and dissenting statement. Louis M. Thayer, Member, was not present and did not participate in the adoption of this report.

REED, Chairman, CONCURRING AND DISSENTING:

I concur in the contents of this study, its conclusions and in all of the safety recommendations, with the exception of the first recommendation. I do not agree that the testing progams proposed should include the closing of highway to a single segment of traffic, e.g., heavy duty trucks. It is my view that such a procedure would be unduly discriminatory. If fog conditions are so hazardous as to require the temporary closing of a highway, I believe it should be closed to all traffic.