WASHINGTON – The largest U.S. trucking group will go to court to challenge Transportation Department driver-fatigue rules that focus on the wrong safety problems and don’t meet legal requirements, it said in a statement.

“We cannot allow this rulemaking, which was fueled by changed assumptions and analyses that do not meet the required legal standards, to remain unchallenged,” Bill Graves, president and chief executive officer of the American Trucking Associations, based in Arlington, Va., said in the statement Tuesday.

While the final rule maintained an 11-hour limit on truckers’ driving day, instead of shortening it to 10 hours as proposed, the industry objects to a requirement of a 34-hour rest period each week that would require drivers to be off two consecutive nights, said Sean McNally, a spokesman for the trucking group.

Many more fatalities and injuries are caused by speeding than fatigue, the group said in its statement. The industry supports regulations that would require installation of speed-limiting devices on trucks, the group said.

Werner Enterprises Inc. and C.R. England are among trucking companies that have objected to a government requirement that the weekly time off include the periods between 1 a.m. and 5 a.m. on two consecutive days. It will reduce flexibility and may undermine safety by forcing drivers onto the road during rush hour, McNally said.

Groups such as Advocates for Highway and Auto Safety had argued that loopholes in previous rules let drivers average 82 hours of work in seven days when they were supposed to be limited to 60 hours.

The trucking regulator is also facing criticisms from safety groups and the International Brotherhood of Teamsters union for sticking with the 11-hour driving maximum. The government was sued in 2003, 2006 and 2009 for allowing 11-hour driving shifts. The third lawsuit was settled with an agreement that FMCSA would redo the regulation.

There were 3,675 truck-related fatalities in 2010.