A messy stretch of Hwy. 401 in Milton is causing major delays Friday morning after a series of collisions triggered a heavy oil leak and forced the closure of two westbound lanes near Regional Road 25, the OPP says.The crashes happened earlier in the morning commute, prompting officers to reduce the highway to a single westbound lane while cleanup and investigation work continue. Police warn that the closure is expected to be lengthy, and drivers should plan alternate routes.Crews are working to manage the oil spill, which has coated part of the roadway and requires extensive cleanup before lanes can safely reopen. Tow trucks and maintenance teams remain on scene.No injuries have been reported so far, but the OPP says the situation has created significant congestion in the area.LANE REDUCTION: Two westbound lanes of #Hwy401 near Regional Road 25 in #Milton are closed following a series of collisions and heavy oil leak in the area. Motorists are advised to plan alternate routes as the closure is expected to be lengthy. ^pia pic.twitter.com/Fhsl59wl5Q— OPP GTA Traffic (@OPP_GTATraffic) May 1, 2026