New studies shed light on how drivers are using the hours of service rule, but offer little proof that the changes made in the name of safety are working.
In the two years since the federal government revamped its hours of service rule, drivers have largely adjusted to the significantly altered 70-year-old regulations.
Many are getting more rest. Most are taking advantage of key provisions that allow for more driving during a typical duty cycle and, in some cases, more hours on the road in a given week. But has the rule made trucking any safer?
That question was addressed by studies released at the 2005 International Truck and Bus Safety and Security Symposium in Alexandria, Va., last November. Their conclusion: The jury’s still out. The studies, however, do give a clearer picture of how the new rule is being used.
The rule allows truckers to drive 11 hours in a duty cycle (up from 10 under the old rule) and restart their week with 34 consecutive hours off duty. It requires truckers to take 10 hours off each day (up from eight hours in the previous rule). The studies found that truckers:
- Drive more daily and weekly;
- Get more rest;
- Like the extra hour of driving and use the 34-hour restart provision, but don’t like being forced to spend more time in their bunks.
The rule, however, has had little impact on safety, according to the Insurance Institute for Highway Safety, which surveyed 1,400 drivers at weigh stations before and after the rule went into effect Jan. 4, 2004. Even though drivers are getting more rest, they are experiencing the same amount of fatigued driving incidents they experienced under the old rule, the study concluded.
It found that 30 percent of participants are driving 10 to 11 hours a day under the new rule and that 80 percent of drivers use the 34-hour restart regularly. Similar numbers were reported last year in a Federal Motor Carrier Safety Administration study.
Instances of driving while fatigued and falling asleep at the wheel, however, did not decrease, reported Anne McCartt of the Insurance Institute. “We believe the increase in off-duty time didn’t offset increased daily and weekly driving,” she said. The institute’s study did not find a substantial increase in fatigued driving, either.
Another study released at the symposium, however, concluded that one productivity provision of the rule may increase accident risk. For truckers who drive up to 11 hours, the risk of an accident goes up substantially as more time is spent behind the wheel, according to a study by Professor Paul Jovanis of Penn State University, among others. The study involved three large carriers during the third quarter of 2004.
The greatest risk was in the 11th hour, when a driver was nearly 3.5 times as likely to have a crash compared to the first hour of driving. In the 10th hour of driving, the risk was 2.5 times more.
That drivers have an increased risk of crashes the longer they are on the road is not a new finding. Other studies – including one released in 2005 that studied 1980s crash data – have shown an increase in crash probability after the eighth hour of driving. Such studies are used by safety activists to argue against additional driving time.
But Jovanis’ study was the first to look at data after changes to the hours rule went into effect. He downplayed the significance of the 11th hour, saying that in fatigue-related crashes, “Time of day is far more important than time on task.” Other studies have shown strong links between accidents and driving after midnight, when the body’s natural circadian rhythms take over.
The American Transportation Research Institute will release a study this month on driver opinions of the new rule. Virginia Dick of ATRI said the feedback was gathered as the rule was implemented in 2004.
The study found that truckers:
- Have more time at home;
- Are more rested and relaxed;
- Find it easier to schedule and track driving time;
- Like the extra hour of driving and the 34-hour restart provision.
“Overall, our driver survey indicated a favorable view of the new HOS rule,” Dick said.
The ultimate measure of the new rule will be its impact on truck-related fatalities. That number slightly increased in 2004, but the rate of fatal accidents per miles driven fell, according to the U.S. Department of Transportation. No completed studies confirm a correlation between increased fatalities and changes in the hours rule – a connection that safety activists, who have repeatedly challenged the rule in court, are looking for.