Major delays are expected along Highway 401 west of London on Thursday night.
According to the Ministry of Transportation, starting at 11 p.m., the westbound lanes of the 401 will be closed from Iona Road to Colonel Talbot Road as crews work to install bridge girders at the Union Road underpass.
Highway 401 westbound traffic will be rerouted via Colonel Talbot Road, Talbot Line and Iona Road, with help from OPP officers at intersections, officials said.
Work is set to wrap up at 6 a.m. Friday.
During this time, Highway 401 eastbound will remain open to traffic with short-term delays, officials said.