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Speeding Truck Hits Signal Equipment in Wyoming

Wyoming FACE Investigation 94WY006


A 31 year old male truck driver died from injuries suffered when the truck he was driving struck the rear of a traffic control vehicle and burst into flames in a high-speed rollover. The driver was alone and had passed several vehicles at speeds of 80 mph on a road posted at 65 mph. He was travelling in the right hand lane and approaching a parked Department of Transportation signal truck that had a mounted flashing arrow signaling traffic to move from the right hand to the left hand lane due to construction ahead.

The truck rear-ended the traffic control vehicle, forcing that vehicle to spin across the left lane and slide into the guardrail on the left side of the road. The signal vehicle then travelled backwards for 22′ causing it to turn clockwise, crossing back into the right hand lane and then coming to rest in the left-hand lane of traffic.

After striking the signal vehicle, the truck continued on in the right lane, applying brakes and going into a skid into the left lane and finally into the median beyond a bridge structure and guardrail. Entering the median, the truck travelled down a bank to the low point of the median, then began travelling up the bank on the other side when it overturned ¼ time onto its right side and burst into flames. The driver of the parked signal vehicle was taken by ambulance to a nearby hospital and the driver of the truck died at the scene from incineration.

Employers may be able to minimize the potential for occurrence of this type of incident through the following precautions:

  • Establish and enforce policy for over-the-road drivers to not exceed speed limits
  • Include safe driving practices as a hiring criteria and enforce safe driving practices as a disciplinary measure.


On a Thursday evening, October 28, 1993 the driver of a tractor trailer was eastbound on an Interstate highway at speeds of approximately 80 mph. He had passed several vehicles and was travelling in the right-hand lane approaching a state Department of Transportation vehicle which was displaying a flashing sequential arrow to divert traffic to the left lane.


Through a reciprocal notification agreement with the Accident Records Section of the Wyoming Department of Transportation, the WY- Wyoming FACE Project was notified of the incident on November 10, 1994. Official reports were requested and received and an investigation was begun on the basis of reports received. Since the incident had occurred several weeks prior to notification, no on-site visit was held.

The incident occurred in daylight, on dry blacktop roads with sufficient visibility to be aware of the upcoming construction area in time to reduce driving speeds and move into the proper lane for a safe traffic flow. There were warning signs, pavement markings, and a truck mounted signal to warn drivers well in advance of the need to form one lane of traffic.

The vehicle was a semi-tractor with a single trailer hauling a cargo consisting of solids in bulk. There were no apparent defects to the vehicle. However, it must be noted that the truck was severely burned and that the cab was virtually destroyed by the fire. At the point where the incident occurred, the Interstate was raised above a dirt road that travelled under and perpendicular to the Interstate Highway. To protect Interstate travelers from dropping onto the dirt road, protective guardrails were in place.

A blood alcohol concentration (BAC) level was determined from a blood analysis of the victim and showed no trace of ethyl alcohol in the blood stream.

The truck travelled 500′ between the point of impact and its final resting place after it overturned. No prior evasive action appears to have taken place. Skid marks begin several feet after the point of impact. The hood of the truck was found approximately 200′ beyond the initial impact point, at about the point where the truck began veering off to the left towards the median.


The Medical Examiner listed the cause of death as incineration as a result of fire in truck cab.


This incident could have been prevented by the victim himself by being alert to driving conditions and reducing his speed to the posted speed limit. There is no indication of alcohol or medical problems that might have caused the driver to be unable to react to the conditions that existed as a result of the road construction.

Wyoming is considered a “bridge state” where Interstate haulers take advantage of the straight, well maintained Interstate roadway that takes them from border to border with minimal traffic flows. Eastbound traffic has no large cities between Salt Lake City, Utah and Omaha, Nebraska, and the Interstate system in this state is well-kept and has a minimum of twists and turns. This type of roadway is often conducive to high speed travel through the state.

Employers who transport through Wyoming should be aware of the hazards of travelling at high speeds, and enforce safe driving practices for drivers within their employee or under contract for hauling. Wyoming speed limits are clearly posted at 65 miles per hour for Interstate roadways. Where temporary construction areas exist; signs, pavement markings, and signals are used to allow for safe travel through construction areas. Entering a construction area at a speed of 80 miles per hour shows wanton disregard for traffic laws and safe driving practices. Out of state transporters should alert their drivers to the potential for traffic crashes and safe driving practices should be used as a criteria for hiring and disciplinary actions regarding over-the-road drivers.


The National Institute for Occupational Safety and Health (NIOSH), Division of Safety Research (DSR), performs Fatal Accident Circumstances and Epidemiology ( Wyoming FACE ) investigations when a participating state reports an occupational fatality and requests technical assistance. The goal of these evaluations is to prevent fatal work injuries in the future by studying the working environment, the worker, the task the worker was erforming, the tools the worker was using, the energy exchange resulting in fatal injury, and the role of management in controlling how these factors interact.

States participating in this study include: Kentucky, Maryland, North Carolina, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia, and West Virginia.

NIOSH Funded/State-based Wyoming FACE Projects providing surveillance and intervention capabilities to show a measurable reduction in workplace fatalities include: Alaska, California, Colorado, Georgia, Indiana, Iowa, Kentucky, Massachusetts, Maryland, Minnesota, Missouri, Nebraska, New Jersey, Wisconsin and Wyoming.

Additional information regarding this report is available from:

Wyoming Occupational Fatality Analysis Program
522 Hathaway Building – 2300 Capitol Avenue
Cheyenne, WY 82002
(307) 777-5439

Please use information listed on the Contact Sheet on the NIOSH FACE web site to contact In-house FACE program personnel regarding In-house FACE reports and to gain assistance when State-FACE program personnel cannot be reached.