Section of Highway 401 in Ontario will be closed to traffic

Drivers who use Highway 401 may face delays this weekend.

A section of the busy route will be closed for 12 hours as the demolition of an old bridge takes place.

Traffic will be diverted off the highway for the demolition, which will see the 401 closed in both directions between Regional Road 25 and Guelph Line near Milton and Halton Hills.

The closure will begin at 9 p.m. Saturday, July 12 and reopen again 12 hours later at 9 a.m. on Sunday, July 13.

Eastbound and westbound motorists will be detoured off the 401 and will follow Campbellville Road, which will take them back to the highway.

Traffic control (including police and flag persons) will be in place, and detour signage will be marked.

The old bridge is being removed because a new one has opened along the realigned Tremaine Road.

It is expected that the new bridge will help with traffic between Steeles Avenue and Campbellville Road and will start off with two lanes before turning into four lanes after further construction.

The project is meant to improve transportation networks in the area to accommodate both future population and employment growth in the western GTA, and in particular, in the rapidly expanding communities of Milton and Halton Hills.

Eventually, the Tremaine route will also create a new interchange at the 401 that will create direct access to the highway. That aspect is expected to open late in 2026. Aside from better access to the highway, the new interchange is also expected to reduce travel times for both commuter and commercial vehicles and improve emergency response access.