The owner of a backhoe that struck the Eastern Avenue bridge and forced the city to close a major thoroughfare during rush hour said yesterday that the equipment had been improperly loaded onto a truck.

Michael Asher, owner Asher Construction Inc. of Carroll County, Md., said his driver, David Ballentine, was southbound on Kenilworth Avenue NE -- part of D.C. Route 295 -- on Tuesday morning when the equipment, on top of a trailer hitched to a dump truck, struck the overpass.

"He miscalculated the height of his load and the height of the bridge," Asher said. "That backhoe can be brought under that bridge if loaded on the trailer the proper way. He just measured incorrectly."

The backhoe scraped the underside of the overpass, dislodging chunks of concrete. No one was injured, but falling debris dented a car and damaged its windshield. Police said two other vehicles sustained damage. The city closed northbound lanes of the road temporarily and reopened them Tuesday night. Southbound lanes were reopened at 4:30 a.m. yesterday.

The bridge over Kenilworth Avenue -- one of the city's lowest -- is 14 feet 2 inches tall, higher, said Bill Rice, spokesman for the D.C. Department of Transportation, than the minimum 13 feet 6 inches required for bridges over interstate highways, which Route 295 becomes in Southeast Washington. New signs have been posted cautioning drivers that vehicles taller than 13 feet 6 inches should avoid the underpass, he said.

John Deatrick, chief engineer for the city Transportation Department, said that the Eastern Avenue bridge is struck about once a year but that "this was the worst." Usually, the accidents are equivalent to "hit-and-runs" and do not require a road closure, he said.

The city had budgeted $300,000 to repair the bridge this year and will now speed up its 2010 date for reconstruction, Deatrick said. After Tuesday's accident, a crew worked 23 hours to repair the damage, he said. City officials did not have a cost estimate for the repairs.

The District has 229 bridges and seven tunnels that are inspected annually, Deatrick said. Inspections this year have found evidence that seven bridges and two tunnels are damaged, he said.

Asher said Ballentine drove under other overpasses Tuesday before the accident, but they were newer, with heights of 16 to 18 feet.

Ballentine was taking the construction equipment to the Pentagon, where Asher's company has a contract to do roadwork.

"He feels horrible because he caused the accident," Asher said. "You don't know how bad. He's never been involved in an accident."

Ballentine was issued a citation for colliding with a fixed object, police said. "It takes two seconds to go underneath the bridge," Asher said. "He hit, and by the time he put on his brakes and stopped, he was on the other side. It's not like a little car, where you stop on a dime."

Northbound traffic on Kenilworth Avenue NE is detoured around the Eastern Avenue overpass Tuesday after a backhoe on a trailer struck the bridge.