In a last ditch effort, the American Trucking Associations (ATA) today asked Congress to block or delay the scheduled July 1 enforcement of changes to the Department of Transportation's (DOT) rules governing a driver's hours of service (HOS) until the agency could prove that the changes would improve road safety.

Steve Williams, chair of the American Transportation Research Institute (ATRI), the research arm of the ATA, told the House Transportation and Infrastructure Committee's highways and transit subcommittee that the rules, which actually took effect in February 2012, are unsupported by data or research.

Williams, who is also chairman and CEO of trucker Maverick USA, argued that the Federal Motor Carrier Safety Administration (FMCSA), a DOT sub-agency that wrote and is enforcing the rules, was not motivated by hard evidence when it set about its work.

"FMCSA's three-paragraph statement in the rulemaking, called 'The Purpose and Need for Regulatory Action,' did not cite any research or data analysis showing a problem. That speaks volumes," Williams testified.

Williams called on Congress to postpone the July 1 enforcement date until FMCSA completes a congressionally mandated study on the rules' impact. The study is slated for completion in September. He also asked Congress to request an independent analysis of the regulation and to require FMCSA to report to lawmakers on any future changes.

At this time, the ball is in the hands of a federal appeals court in Washington, which has been asked to rule on the industry's appeal to overturn the rules. In March, the court heard arguments from both sides. However, the fact that it has yet to rule at this late date has led most observers to believe that enforcement will begin on July 1 as scheduled.

In February, the FMCSA denied a request by various manufacturing, shipper, and carrier groups for either a three-month delay in the July 1 enforcement date or a similar delay should the appeals court back the agency. FMCSA said the groups didn't offer a valid reason for delaying the compliance date and that the public would be denied three months of enhanced safety if their request was granted. FMCSA said parties in the trucking supply chain have been given 16 months to prepare and adjust to the new rules.

Thomas E. Bray, HOS expert at J.J. Keller & Associates Inc., a Neenah, Wis.-based consultancy, said it would be virtually impossible for the House and Senate to pass their own bills, for House-Senate conferees to then reconcile the competing versions, and for President Obama to sign a bill into law, all by July 1.

Congress could have become involved during last year's writing of legislation to re-authorize transport funding programs, Bray said. However, it did nothing but mandate a FMCSA field study.

Under the new rules, a driver's seven-day workweek will be reduced to 70 hours from 82. For the first time, drivers will have limits placed on their traditional 34-hour minimum restart period, requiring it to occur once every seven days and to include two rest periods between 1 am and 5 am over two consecutive days. Drivers are also required to take a 30-minute break after driving more than eight hours. FMCSA left unchanged language allowing 11 hours of continuous drive time after a driver has spent 10 consecutive hours off duty.

Shippers and truckers said the reduction in truck miles driven will cut productivity by between 3 and 5 percent. Williams estimated that a 1.5-percent to 4-percent reduction translates into a $500 million to $1.4 billion drop in productivity.

Williams said FMCSA is attempting to apply a solution to a problem that is already well on its way to being solved. He cited an ATRI report finding "statistically significant" declines in the number of crashes under the current rules. For example, there has been a 31-percent drop in preventable collisions between 2004 and 2009, he said.

FMCSA has said in the past that the rule changes will yield $160 million to $280 million of annual "net benefits," most in the form of improved driver wellness and performance. The trucking industry disputes that claim, however.