Oral arguments in the lawsuit challenging the hours of service rule will be held March 15 at the U.S. Court of Appeals for the District of Columbia Circuit.

It typically takes the court two to three months to rule following arguments, which means it should hand down its decision before the new HOS rule is scheduled to take effect in July.

At issue are petitions by trucking interests asking the court to strike four provisions of the rule, and by safety advocates charging that the Federal Motor Carrier Safety Administration erred when it preserved the 34-hour restart and 11-hour driving limit.

American Trucking Associations and others object to a change in which the 34-hour restart will be limited to once a week, with each restart including two rest periods between 1 a.m. and 5 a.m.

They also object to the requirement that a driver must take a half-hour off if its been more than eight hours since he took an off-duty or sleeper berth break.

They contend that the rules established in 2004 work well and have contributed to significant improvements in industry safety.

Public Citizen and its allies have told the court that the agency abused its discretion when it preserved the restart and the daily limit. They also say the agency erred in its decision not to eliminate the 11-hour limit on daily driving.

FMCSA, for its part, contends that limits on the 34-hour restart are reasonable, that the productivity savings outweigh the risks of the 11-hour limit, and the 30-minute rest break improves safety.