ARLINGTON, Va. -- Despite what special interest groups and unions are claiming, the current hours-of-service framework in the U.S. is very safe, but more flexibility which allows drivers to choose their own rest periods would be nice, says the American Trucking Associations.

The comments are part of ATA's submission to the Federal Motor Carrier Safety Administration on hours of service rules.

While the ATA says the current rules are working fine, it called for the regulator to return flexibility to drivers' time off in the form of a sleeper berth provision.

The agency removed the provision from the original 2004 final rule after being pressured into doing so by the US Court of Appeals, which ruled on a challenge to the rules by Public Citizen.

The decision, widely criticized by both carriers and owner-operator groups, removed the ability for drivers to obtain the necessary 10 off-duty hours by splitting their sleeper berth in two periods of their own choosing, as long as one was a minimum of two hours long.

Unlike Canada, which includes a similar sleeper berth allowance, drivers in the U.S. must "rest" for eight hours in a row, and take another two consecutive hours off-duty before resetting their daily driving schedule.

In its comments to FMCSA, the trucking association said the rules have contributed to improved safety since 2004, noting that the truck-involved fatality rate dropped 12.3 percent in 2008 from 2007 -- the largest year-to-year drop ever recorded and the fifth straight year the fatality rate has fallen.

ATA told the FMCSA it should focus on addressing the true causes of fatigue in transportation, including:

Sleep disorder awareness, training and screening; promoting the use of fatigue risk management programs; evaluating the use of fatigue detection devices; and increasing the availability of truck parking on important freight corridors.