The Oklahoma Transportation Commission declared an emergency Monday after learning that more than half of the 95 piers that support Oklahoma City’s heavily traveled Belle Isle bridges on Interstate 44 had sustained structural damage because of salt and weather.

Commissioners ordered transportation officials to solicit bids to make repairs. Cost is expected to top $7 million, said Mike Patterson, executive director of the Oklahoma Transportation Department.

On April 16, officials closed one of three lanes in each direction on I-44 between Pennsylvania and Western avenues. They also closed the eastbound on-ramp from the Northwest Expressway and the westbound off-ramp to the Northwest Expressway.

Oversized and overweight vehicles have been banned from the bridges until all repairs are completed.