Federal regulations limit the number of hours commercial truck drivers may stay on-duty. These rules have been modified over the years in an effort reach a balance between safety and efficiency. Currently, the rules impose daily and weekly limits on the number of hours commercial truck drivers are permitted to work.  Generally, drivers are permitted to work no more than 14 consecutive hours. Of that time, only 11 hours may be devoted to driving. (The remaining time may be devoted to paperwork, loading and unloading, etc.) After exhausting these limits, drivers are required to spend a minimum of 10 consecutive hours off duty. The regulations also prohibit driving after being on-duty more than 60 hours in 7 consecutive days, or 70 hours in 8 consecutive days. Drivers may restart the 60 or 70 hour clock by taking no less than 34 consecutive hours off duty.

A recent Federal Motor Carrier Safety Administration (FMCSA) study sheds light on whether these regulations, if properly followed and enforced, are likely to be effective. (See Analysis of Risk as a Function of Driving-Hour: Assessment of Driving Hours 1 through 11 Final Report. The shorter ‘Tech Brief‘ summary is here.) This study does not support the hypothesis that driving 10 or 11 hours is more unsafe than driving fewer hours. In fact, the study suggests that driver performance in hours 2 through 11 is about the same. Oddly, drivers performed worst during the first hour of driving.

Overall, the study concludes that “time on task” is a poor predictor of driver performance. More relevant, the study suggests, is time of day. The highest incidence of unsafe performance occurred during times of heavy traffic conditions.

This entry was posted on Wednesday, October 15th, 2008 at 12:56 pm and is filed under Truck Safety News, Truck Safety Regulations. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.