Commuters who planned to use Highway 401 overnight Monday and early Tuesday morning may have to find an alternate route, as the westbound lanes will be fully closed to traffic for six hours.

Ontario's Ministry of Transport says the highway's westbound lanes will be closed between Townline Road and Hespeler Road from 11:00 p.m. Monday to 5:00 a.m. Tuesday.

The same lanes will be closed again overnight from 11:00 p.m. Tuesday to 5:00 a.m. Wednesday.

The ministry says the closure is to allow "for the installation of bridge girders at the new Franklin Boulevard Bridge."

During the closure, traffic will be redirected along Pinebush Road to Hespeler Road. The ministry says drivers should expect delays through that area.

The Franklin Boulevard off-ramp, which is used to exit off the highway when travelling eastbound on Highway 401 and was closed on Sept. 10, is closed and will remain closed until Sept. 24 while construction continues on the bridge.