If your travel plans include a trip on Highway 401 west of London this weekend, this is a road closure you need to know about.

Starting at 10 p.m. on Saturday and continuing until 8 a.m. on Sunday, a 20-kilometre stretch of Hwy. 401 will be closed in both directions between Colonel Talbot Road west to Iona Road.

According to Ontairo's transportation ministry, the closure is needed so crews can demolish the Mill Road underpass.

During the closure, Highway 401 traffic will be rerouted via Iona Road, Talbot Line and Colonel Talbot Road with OPP assistance at intersections. Although traffic will eventually get through, the province says drivers can expect "major delays" in the area.

OPP Sgt. Kevin Martin says drivers caught up in the closure may get frustrated, but he says they still need to obey the rules of the road.

He said drivers should avoid the temptation to make illegal U-turns or cut in front of other drivers.

"Not only are those really risky behavours, not only are they illegal, but the possible consequence is a collision that could involve a serious injury or a death," he said.

Again, the closure is slated to end by Sunday at 8 a.m.