Traffic in a west Cambridge industrial area is about to get a whole lot messier.

Speedsville Road is now closed down on either side of Highway 401 as crews work to demolish and replace the highway bridge over the road.

The work is expected to take anywhere from five to seven months – but it’s the first seven days that could be some of the worst for traffic concerns.

Once the existing bridge is demolished, the 401 will be closed over Speedsville from 10 p.m. Saturday to 7 a.m. Sunday.

Vehicles will be diverted along Hespeler Road, Maple Grove Road and King Street to continue using the highway.

After the 54-year-old bridge is demolished, crews will work to build a new, wider bridge.

Periodic lane closures are expected through the summer, while the full 401 will be closed two more times – once in August and once in September.

Detours are in place, with traffic that would normally head northbound on Speedsville asked to use Eagle Street, Hespeler and Maple Grove to reconnect with Speedsville, while southbound traffic will be sent along Maple Grove, Fountain Street and Eagle.

The closure of Speedsville is part of a long-term project to widen the 401 in Cambridge.

In 2015, Fountain Street will receive the same treatment.

The full project – including Fountain, Speedsville and work on the Highway 8-to-Highway 401 ramp – will cost $16.9 million.