Traffic engineers are working to repair the Route 1 Bypass bridge between Maine and New Hampshire that became stuck in the open position at about 1:30 p.m., possibly because of the extreme cold.

A spokesman for the Maine Department of Transportation said crews don’t expect to have the Sarah Mildred Long Bridge back in operation until after the evening commute.

Initial evaluations suggest extreme cold weather may be affecting the drawbridge’s operation, said Ted Talbot, MDOT spokesman.

Memorial Bridge carrying Route 1 traffic between Kittery and Portsmouth is already closed for major repairs and so all traffic crossing that section of the Piscataqua River is being rerouted to the Interstate 95 bridge.