HARRISBURG, Pa.—Major interstates around Philadelphia were ordered closed as megastorm Sandy passed over the state, while many other local roads and bridges were being closed due to flooding or debris.

Gov. Tom Corbett ordered the highways closed from 7 p.m. Monday to 2 a.m. Tuesday. The highways included the full length of Interstates 95 and 676; the portion of I-476 south of the Pennsylvania Turnpike; I-76 from the turnpike to Passyunk Avenue in Philadelphia; and the U.S. Route 1 extension in Philadelphia. Emergency vehicles could still travel the roads.

A Pennsylvania Turnpike Commission spokesman said Monday night that the agency expected to keep the highway open but close the turnpike bridge across the Delaware River into New Jersey because of high winds and lighting failures. The westbound lanes from New Jersey were already closed, the spokesman said.

Four other Philadelphia-area Delaware River bridges—Walt Whitman, Ben Franklin, Betsy Ross and Commodore Barry—were closed, except to emergency vehicles, the Delaware River Port Authority said.

The Pennsylvania Department of Transportation said Monday night that more than 200 bridges and roads were closed because of downed trees, power lines and flooding, most of them in southeastern Pennsylvania.

The storm was on track to pass over the Philadelphia area, heading westward along Pennsylvania's southern counties. The storm's center was expected to pass south of Harrisburg by 2 a.m. and State College by 2 p.m. on Tuesday.

Wind gusts were expected to be around 70 miles per hour, with sustained winds at 40 to 50 mph, Corbett said. The storm could reach as far west as the Johnstown area before veering north.