A one-mile section of the Beltway in eastern Baltimore County, closed last night after a 230,000-volt power cable fell across the highway, was reopened to traffic about 4:30 a.m. today, said Arthur Slusark, a spokesman for the Baltimore Gas and Electric Co.

Mr. Slusark said BG&E; workers rehung the cable, but further work will require Interstate 695 to be closed from 10 o'clock tonight until 2 a.m. tomorrow. About 5 p.m. yesterday, the power cable fell across the highway, injuring a Glen Burnie woman when it struck the windshield of a pickup truck.

The cable, which crossed the highway near Rosedale, shorted out before it hit the road. Customers did not lose power, Mr. Slusark said.

The cable, which hung from a metal tower, was part of a link between BG&E;'s Riverside generating station in Dundalk and a substation in eastern Baltimore County.

Lana McAllister, 40, of the 200 block of Roosevelt Ave., received minor cuts when the cable shattered the windshield of a truck driven by her husband, Walter, police said. She was treated at the scene.