Several large trucking fleets have urged the Federal Motor Carrier Safety Administration to retain the 11th hour of driving and the 34-hour restart in its hours-of-service regulations, saying those provisions have improved highway safety and given drivers the flexibility to adjust to unexpected delays, Transport Topics reports.

“UPS has not experienced adverse safety effects resulting from use of the 11-hour driving rule,” UPS Vice President Tom Jensen wrote in comments to the agency. “In fact, UPS’ domestic auto accident frequency has declined every year since the introduction of the rule, decreasing nearly 23 percent from 2004 to 2007.”

UPS was among the carriers who already have filed comments with FMCSA on its interim fleets final rule. The comment deadline, which originally was Feb. 15, has since been extended until March 17.

Jensen told FMCSA that employee injuries fell to 16,732 last year, from 23,704 in 2004. He also said the 11-hour rule enhanced the safety record of the company’s less-than-truckload unit, UPS Freight.

UPS purchased Overnite Transportation in 2005. The company has since been renamed UPS Freight.

Other large fleets reported similar reductions in accidents.

Herb Schmidt, president of Con-way Truckload, told the agency that from 2004 to 2006, “our overall DOT recordable accident frequency improved by 22 percent.”

Schmidt added that the company formerly known as Contract Freighters Inc. “has enjoyed a 53 percent decrease in driver log violations” between 2004 and 2007.

Don Osterberg, vice president of safety and training for Schneider National, said that the company’s serious accidents have reduced in number and frequency since the rule was instituted.