The death toll from highway work zone accidents seems never-ending. And with another accident on the eve of a report on an earlier deadly mishap, questions again are being raised over whether stricter controls are needed.

On Feb. 6, the driver of a tractor-trailer apparently fell asleep on Interstate 15 in a construction zone in Barstow, Calif., waking just as he approached several cars exiting the highway. The tractor-trailer struck one car, setting off a firey chain reaction that led to four deaths. An investigation is under way.

The accident occurred at a California Dept. of Transportation project where general contractor Yeager Skanska Inc., Riverside, Calif., a unit of Skanska USA Civil Inc., is performing a $120-million widening of I-15, from Victorville to Barstow. Started in late 2002, the two-phase project will add a 12-ft-wide concrete third lane and shoulder to both north and southbound traffic.

Temporary concrete median barriers were being used to redirect vehicles so construction crews could work unobstructed. "There was actually a shoulder area where cars could pull off to one side," says Holly Kress, a Caltrans spokesperson. "I understand that one of the drivers fell asleep. There’s nothing you can do to make a highway safe from an accident like that," she adds.

That incident occurred four days before the National Transportation Safety Board released its findings on another work zone accident–an Oct. 13, 2001, bus accident that killed four on a stretch of U.S. Route 6 in Omaha. NTSB determined that the probable cause of the accident "was the failure of the Nebraska Dept. of Roads (NDOR) to recognize and correct the hazardous condition in the work zone created by the irregular geometry of the roadway, the narrow lane widths, and the speed limit." The report also cites the bus driver’s inability to maintain the bus within the lane due to the perceived or actual threat of a frontal collision with an approaching vehicle.

But NDOR disagrees. It claims that it "fulfilled its duty to the traveling public and maintains that the probable cause of the accident was through no fault of the NDOR or the State of Nebraska."

NTSB concluded there were several problems, including high speed limits, poor traffic controls and hazardous roadway geometry. NDOR and the contractor, Charles Vrana and Sons Construction Co., Omaha, also failed to adequately maintain the barrier system in one corner of the site, claims NTSB.

The engineering and design of a work zone can always be improved, says Jennifer Gavin, a spokeswoman for the American Association of State Highway and Transportation Officials.