The National Transportation Safety Board's investigation of last week's crash that killed 11 people is still in its infancy, but among the causes investigators are looking into are whether the driver fell asleep, was impaired or suffered a medical condition that caused him to lose control.
"We don't yet know what all the issues are that this investigation is going to turn up," NTSB spokesman Peter Knudson said.
What is known is the Federal Motor Carrier Safety Administration gave Hester Inc. of Alabama, the trucking company involved in the crash, a "deficient" rating of 88.4 in February based on inspections of the company's 30 drivers during the past 30 months. The agency uses a scale of 1 to 100, with 100 being the worst score.
At least 13 of Hester's drivers' violations were for driving too many hours during that time period, according to the administration.
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While the cause of the recent crash is unclear, one trucking expert said the company's record was clear.
"The safety rating for that trucking company indicated that it should not be operating without some intervention from the Department of Transportation," said Clayton Boyce, a spokesman for the American Trucking Associations.
There was no answer to a phone call to Hester's offices Wednesday.
One aspect of trucking that some officials say could be improved is getting tired truck drivers off the road. For more than 30 years, the NTSB has called for electronic onboard recorders to improve safety in commercial trucking by monitoring the number of hours drivers work.
But the Federal Motor Carrier Safety Administration has not adopted those rules, saying only 7 percent of large truck crashes are fatigue-related.
A spokesman for the American Trucking Associations said Wednesday a revised rule regarding the recorders could come out as early as Friday. He said his organization had not seen the rule.
Last week's crash on Interstate 65 may bring renewed attention to onboard recorders.
The driver of Hester's tractor-trailer, Kenneth Laymon, 45, of Jasper, Ala., crossed the median of Interstate 65 near Munfordville on Friday at 5:15 a.m. and slammed into a van, killing 10 people and himself, Kentucky State Police said. The others who died were Mennonites traveling to a wedding in Iowa. Two young children survived the crash.
"In the southbound lane there were tire tracks departing the highway at a shallow angle onto the median. We did not document any skid marks on the highway," Knudson said.
Skid marks on the highway would have indicated the driver was attempting to stop or having problems controlling the truck.
Knudson said the NTSB's on-scene investigation should be complete later this week. After that, investigators will await toxicology reports on Laymon.
'More precise information'
Under federal regulations, a commercial truck driver can't drive for more than 11 hours and can't be on duty more than 14 hours.
An electronic onboard recorder, which looks like a small laptop computer mounted in the cab, could provide information to the driver about his next destination or the weather. But, more importantly, the device automatically records whether the truck is running and how many hours a driver has logged.
Some trucking companies voluntarily have recorders in their fleets, but Knudson did not know whether there was one aboard the truck in Friday's crash.
If there was and it survived the fire, "then we would have more precise information about the hours that that truck had been operating and how long that driver had been behind the wheel," Knudson said, which might help to pinpoint the cause of the crash.
NTSB first advocated the use of onboard recorders to increase compliance on driver hours in 1977. Under a 2007 FMCSA proposal, trucking companies that had a history of serious non-compliance with hours-of-service rules would have been subject to mandatory installation and use of recorders for a period of two years.
NTSB found that idea unsatisfactory because only an estimated 930 of the 700,000 carriers in operation would be affected by the requirement within the first two years of the rule's enforcement.
In accidents where the truck driver is at fault, the number one cause is driving too fast for conditions, followed by reckless driving and inattention, according to several studies.
'Don't improve safety'
In November 2008, the U.S. Department of Transportation sent a draft of the final rule on recorders to the Office of Management and Budget for review. But the Obama administration shelved it and all other federal rules under review in January 2009.
The FMCSA did not return calls Wednesday regarding the issue of recorders.
"The devices don't improve the safety of the vehicle or the driver," said Todd Spencer, executive vice president of the Owner-Operator Independent Drivers Association, which opposes mandatory recorders. "The fact that they can record hours of operation is simply mythical," he said, because they don't record hours of activities that contribute to fatigue, such as loading and unloading.