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Highway 401 conditions from Windsor to Quebec border
Highway 401 Road Conditions in Ontario
Radar and live pavement conditions on the 824 km of Highway 401 from Windsor to Quebec border — plus the summits it crosses and the winter tire rule in force on it.
Updated Sep 20, 2026 8:18 AM EDT · Mostly dry, wet in places
Lowest 7°C near Cornwall · Highest wind 14 km/h near Oshawa
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Highway 401 runs 828 km from the Gordie Howe bridge at Windsor to the Quebec line, through London, Toronto, Oshawa and Kingston: the busiest highway in North America through Toronto, and between Chatham and Woodstock the one the Lake Huron snow squalls close — 400 crashes in one December morning in 2025, 50 vehicles in one pile-up near Belleville in January 2026. No winter tire law applies; the province recommends them.
- Runs from: Windsor to Quebec border
- Length: 824 km
- Local name: Macdonald–Cartier Freeway
- Winter tires: Not required by law; recommended
Weather data from Sep 20, 2026 8:18 AM EDT
7°C
16°C
14 km/h
101.3-101.7 kPa
38 current reports along the route, including 1 full closure. The 3 most serious are listed below. Always check with Ontario 511 before setting off.
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Road closed
Closure on HWY 401 Westbound
Nightly Construction (Cancelled for Today) on HWY 401 Westbound Express between RENFORTH DR, Toronto and WINSTON CHURCHILL BLVD, Mississauga. ALL LANES CLOSED.
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Lanes blocked
Road work on HWY 401 Westbound
Nightly Construction on HWY 401 Westbound On-ramp at BROCK ROAD, Pickering. ALL LANES CLOSED.
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Lanes blocked
Road work on HWY 401 Eastbound
Continuous Construction on HWY 401 Eastbound On-ramp at Highway 4 / Colonel Talbot Rd, London. ALL LANES CLOSED.
Segments and what to expect
Highway 401 is not one road in winter but seven, and the names below are the ones drivers and Ontario 511 use for them. The elevations are the province's own, from its cameras at the places named.
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Windsor to Tilbury and Chatham
Flat, straight and fast out of the Gordie Howe bridge: the stretch west of Tilbury that earned the name Carnage Alley for its crashes, where fog off Lake St. Clair and the first squall lines meet the truck traffic from Detroit.
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Chatham to London
The snow squall belt. Snow off Lake Huron crosses the highway here in bands a few kilometres wide, dry road to whiteout in a minute and back; nearly every winter pile-up on the 401 is somewhere between Chatham and Woodstock.
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London to Woodstock and Kitchener
Still squall country as far as Woodstock — Highway 401 westbound from Cedar Creek Road to Woodstock closed for collisions on 13 March 2026 — then the climb onto the Waterloo moraine, the highest, snowiest ground the road crosses.
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Milton to Toronto and Pickering
The collector-express system through Mississauga and Toronto, up to 18 lanes and more than 450,000 vehicles a day: North America's busiest highway. It closes for crashes, not weather, and a first snowfall slows it to a walk.
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The Highway of Heroes: Pickering to Trenton
Oshawa, Bowmanville, Port Hope and Cobourg along the Lake Ontario shore: lake-effect snow off the open water in December and January, and drifting where the road runs across the open fields north of the lake.
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Trenton to Kingston
Belleville, Napanee and Kingston, where the squalls off Lake Ontario are at their worst — on 27 January 2026 they closed the road between Belleville and Trenton for most of a day after some 50 vehicles collided.
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Kingston to the Quebec border
Along the St. Lawrence through Brockville and Cornwall to the Quebec line: the coldest part of the road, freezing rain from the Ottawa Valley systems, and Autoroute 20 on the other side.
Closures that have shaped Highway 401
Not a log of every hour Ontario 511 has shut a lane — the events that say what kind of road this is, each with the source it comes from.
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Westbound Highway 401 from Cedar Creek Road near Cambridge to Woodstock closed at about 12:15 p.m. on 13 March 2026 for multiple collisions in heavy snow and winds to 110 km/h, part of a day of closures across southern Ontario. Source: CambridgeToday, 13 March 2026.
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Snow squalls off Lake Ontario on 27 January 2026 closed Highway 401 in both directions between Wallbridge-Loyalist Road on Belleville's western edge and Glen Miller Road in Trenton for much of the day, after collisions involving about 50 vehicles. Source: Ontario Association of Fire Chiefs, 27 January 2026.
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Wet, heavy snow and snow squalls on the morning of 10 December 2025 brought 400 crashes in southwestern Ontario before noon, injured two OPP officers, and closed the westbound 401 in London twice — at Wonderland Road and between Highbury Avenue and Wellington Road — behind jackknifed trucks. Source: CBC News London, 10 December 2025.
Alternate routes when Highway 401 is closed
- If Highway 401 between Tilbury and London is closed: Highway 40 to Sarnia, then Highway 402 — about 10 min longer than the direct road when both are open, 232 km against 209 km. The northern freeway route by Sarnia. The same squalls cross the 402 too, so it is a way round a closed road rather than round the weather.
- If Highway 401 across Toronto is closed: Highway 407 ETR, the toll road across the top of the city — about 10 min longer than the direct road when both are open, 121 km against 102 km. Tolled by distance and empty for it: the road the 401's traffic moves to when a crash closes the collectors and the express together.
- If Highway 401 between Belleville and Kingston is closed: Highway 2 through Napanee — about 10 min longer than the direct road when both are open, 92 km against 85 km. The old road beside the new one, two lanes through the towns. On a squall day it is in the same snow a kilometre south.
Distances and times are measured over openrouteservice on a clear road; a closure day is not one, because the detour carries the closed road's traffic too. What is closed right now is on Ontario 511 ↗.
Highway 401 Winter Driving FAQ
- How long does Highway 401 take from Windsor to Toronto?
- About 410 km — 209 km from Windsor to London and 199 on to downtown Toronto as openrouteservice measures them — and a little over five hours at its clear-road speeds. The stretch that changes that is Chatham to Woodstock, where a snow squall off Lake Huron can close the road for hours with no warning in the Windsor forecast.
- Do I need winter tires to drive Highway 401 in winter?
- Not by law. Ontario has no winter tire requirement; the province recommends them and every insurer must offer a discount if you fit them. West of Woodstock, in the squall belt, they are the difference between stopping and joining the pile-up.
- What is a snow squall and why does it close the 401?
- A narrow band of heavy snow generated when cold air crosses the open water of Lake Huron or Lake Ontario: a few kilometres wide, intense, and moving. Traffic at 100 km/h drives from dry pavement into a whiteout within a minute, and the chain-reaction crash closes both directions. Environment Canada issues snow squall warnings for exactly this.
- What is the alternative when the 401 is closed?
- West of London, Highway 402 by Sarnia; across Toronto, the tolled Highway 407; between Belleville and Kingston, Highway 2 through Napanee. Each is measured on this page against the direct road — and each is in the same weather.
- Is Highway 401 the busiest road in North America?
- Yes, through Toronto: the section between Renforth Drive and Highway 427 carries an annual average of about 450,000 vehicles a day and more than half a million on some days, over up to 18 lanes of collector and express roadway.
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