More than five weeks after a federal appeals court threw out a 2010 federal electronic onboard recorder rule, Federal Motor Carrier Safety Administration officials remain silent about whether they will restart the regulatory process outright with a new proposed rule, or issue a supplementary rule.

Proposed regulations to change maximum truck driver hours and require electronic onboard recorders for almost all trucks are among the most costly rules currently being considered by the Obama administration, the president wrote in a letter.

Trucking is attacking a federal regulation issued last month that will require employers to hang posters informing workers about their rights to form and join unions.

Caterpillar Inc. will pay $2.55 million to the federal and California governments to settle claims it sold engines without proper emissions controls and violated emissions control reporting and engine labeling regulations, the U.S. Environmental Protection Agency said.

The National Transportation Safety Board last week issued a slate of comprehensive regulatory recommendations aimed at reducing the number of cargo tank truck rollovers by mandating the installation of roll stability technologies and improved cargo tank design.

The Federal Motor Carrier Safety Administration said it wants to extend its regulatory reach over the next five years to include not only trucks and buses but also shippers, brokers and receivers.

WASHINGTON — Trucking is burdened with “regulatory overload,” an American Trucking Associations official told a panel of Department of Transportation officials.