Detours will be in place this weekend on Highway 400, as work gets underway on two major construction projects.

Beginning at 10 p.m. on Friday, one southbound on-ramp will be closed at Highway 400 and Duckworth Street. The closure will allow crews to demolish the old Duckworth overpass.

"The last major portion is just the construction of Duckworth Street underneath the 400,” says Stew Patterson, a spokesperson with the City of Barrie. “Widening from the existing two lanes to six lanes."

Duckworth Street will also be closed while work is done on the $42 million project.

Starting on Thursday night, crews will begin shifting northbound traffic on Highway 400 from the old Duckworth Street overpass to the new one.

The closure is expected to remain in place until 5 a.m. on Monday.

"We feel that the detour route will convey a majority of the traffic quiet easily."

A little further south on Highway 400, crews will be tearing down the McKay Road overpass. That means both directions of the highway will be shut down between Innisfil Beach Road and Mapleview Drive.

The shutdown will start at 11 p.m. on Saturday and is expected to reopen early Sunday morning.

Officials hope to have the highway reopened before people start heading home from the cottage.