U.S. Class 8 truck orders continued to slump in May, dropping 23% from year-ago levels and declining for the fifth consecutive month as economic, financial and regulatory uncertainty dampened fleets’ buying decisions, analysts said.

O&S Trucking, Springfield, Mo., has filed for Chapter 11 bankruptcy protection, the Springfield News-Leader reported Thursday.

U.S. fleets bought 16,905 new heavy-duty trucks in April, a 38.9% jump over the corresponding period of 2011, WardsAuto.com reported.

ARLINGTON, Va. — American Trucking Associations President Bill Graves blasted federal lawmakers in a recent speech, telling an audience of a shippers’ association here that the upcoming election has halted the legislative process and Republicans’ pushes to decrease the federal role in transportation are missing the mark, among other criticisms.

The decline in truck orders — including the 55% drop last month compared with a year ago and declines in the previous three months — represents a “pause” in the fleet replenishment process rather than a sign of fundamental market weakness, several analysts and dealers have said.

SAN FRANCISCO — Two of trucking’s leading economists said last week the industry’s economic recovery was well under way and should continue for at least several more years.

U.S. Class 7 sales jumped 20.3% in March compared with the same month last year, while Class 6 sales rose just 1.6%, WardsAuto.com reported.

USA Truck reported a first-quarter loss, citing a sharp increase in its unmanned tractor count.

Trucking continues to be the dominant U.S. mode of freight transportation, hauling 67% of freight last year, according to a new American Trucking Associations report.