A-40 in Repentigny to close overnight August 18-19, 2026 for roadwork
Highway 40 in Repentigny will shut down overnight from 10 p.m. on August 18, 2026, to 5 a.m. on August 19, 2026, according to Québec 511’s Autoroute 40 current conditions page. During the closure, the clearance height on the affected stretch drops to 4.3 meters, a restriction that typically points to work happening on a structure above the roadway, such as a sign gantry or overpass beam. Drivers heading through Repentigny that night should plan for a detour and build in extra travel time before the highway reopens at 5 a.m.
This is a single overnight closure tied to a scheduled road work window, not an incident-driven shutdown. That distinction matters for anyone commuting through the region in mid-August, since planned closures come with advance notice and posted detours, while incident closures do not.
Quick summary for drivers
- The A-40 closure in Repentigny runs from 10 p.m. August 18, 2026 to 5 a.m. August 19, 2026, a seven-hour overnight window.
- Clearance height drops to 4.3 meters during the closure, so oversized vehicles and high-profile trucks need to plan an alternate route regardless of the detour signage.
- Use Québec 511 (quebec511.info) or the 511 mobile app before you leave to confirm the closure is still active and check whether it has been extended.
- Expect detour traffic routed through L’Assomption and local Repentigny and Charlemagne streets, so budget 15 to 25 extra minutes if you normally use this stretch of the A-40 overnight.
- If you’re driving a commercial vehicle over 4.3 meters, do not attempt this section during the closure window even if signage suggests a detour; confirm clearance on alternate roads first.
Closure details: dates, times, and affected sections
Exact closure window and reduced clearance height
The closure is scheduled for a single night: 10 p.m. on Tuesday, August 18, 2026, through 5 a.m. on Wednesday, August 19, 2026. Québec 511 lists the affected location simply as “40 À Repentigny,” with the reduced clearance height of 4.3 meters flagged as an active condition for the duration of the work. A 4.3 meter clearance is roughly 14 feet, low enough to affect standard tractor-trailers and RVs, even though it’s a temporary restriction rather than a permanent one.
Overnight windows like this one are standard practice for structural work above provincial highways in Quebec, since they minimize disruption to daytime commuter volume on one of the busiest corridors connecting Montreal’s northeast suburbs.
Which lanes and direction are affected
Québec 511’s listing references a “major direction” closure without specifying full details on lane configuration in the public advisory text. In practice, overnight clearance restrictions of this kind usually mean one direction of Highway 40 remains open with reduced lanes while crews work on the structure above the closed side. Drivers should not assume both directions are fully open. Check the live Québec 511 map before departure, since the exact lane and directional breakdown can shift as the work crew adjusts the site.
“40 À Repentigny, From August 18, 2026 at 10 p.m. to August 19, 2026 at 5 a.m. … Clearance height reduced to 4.3 meters.”
Source: Québec 511, Autoroute 40 current conditions advisory
Why the closure is happening: Transport Québec’s road work schedule
Transport Québec schedules overnight highway work throughout the summer to take advantage of lower traffic volumes and cooler overnight temperatures, both of which matter for asphalt and structural repairs. The Repentigny closure fits this seasonal pattern of A-40 road work, which typically runs from May through October across the Montreal region.
Scope of the August 2026 construction project
The specifics of the August 2026 work order aren’t broken out in Québec 511’s public listing beyond the closure window and clearance restriction. Still, the reduced overhead clearance is the clearest signal available: it points to work on a structure spanning the highway, rather than surface repaving, which wouldn’t typically require a height restriction. Drivers with high-clearance vehicles should treat the 4.3 meter limit as a hard constraint for the full duration of the window.
Detour routes for drivers
Highway 40 detour via L’Assomption
For the overnight closure, traffic exiting the affected section of Highway 40 is expected to be routed toward L’Assomption, using Route 138 to bypass the closed segment before rejoining the A-40 corridor further along. This mirrors how Transport Québec has handled comparable overnight closures on this stretch in past construction seasons: local arterial roads absorb the diverted volume for a few hours rather than a formal long-distance bypass. Because traffic volume overnight is lower, the detour adds time rather than causing gridlock, but it’s still worth 15 to 25 minutes of buffer if you’re traveling through the area between 10 p.m. and 5 a.m.
Alternate routes through Repentigny and Charlemagne local roads
Drivers familiar with the area have local options beyond the posted detour. Boulevard Iberville and Notre-Dame street through Repentigny and Charlemagne provide east-west alternatives that run roughly parallel to this section of the A-40. These roads carry more stop lights and lower speed limits, so they won’t match highway travel times, but they stay open when the A-40 doesn’t and give commercial drivers with height-restricted vehicles a way around the 4.3 meter limit entirely.
How this fits into broader Montreal northeast highway closures
Recent Highway 40 incidents in Repentigny (context and pattern)
This scheduled closure follows a pattern of disruption on this specific stretch of highway. In a separate, unplanned incident, Highway 40 in Repentigny reopened just before 5 p.m., almost 12 hours after it had closed due to a collision involving four trucks, according to a regional traffic report covering closures on Highway 40 and the Mercier bridge corridor. That closure had no advance notice and stretched across a full workday, a contrast worth noting against the scheduled, time-boxed nature of the August 18-19 road work.
The difference matters practically: planned closures like this one come with a defined end time and posted detours in advance, while incident closures like the four-truck collision can extend for hours with no fixed reopening estimate. Drivers should treat the two categories differently when deciding how much of a delay to plan for.
| Closure type | Duration | Advance notice | End time certainty |
|---|---|---|---|
| August 18-19, 2026 road work (Repentigny) | 7 hours (10 p.m. to 5 a.m.) | Yes, posted in advance | High, fixed schedule |
| Four-truck collision closure (Repentigny) | Approximately 12 hours | None | Low, cleared when scene reopened |
Other planned closures on the A-40 corridor this summer
The Repentigny closure is one entry in a wider set of Montreal northeast highway closures affecting the A-40 corridor this summer. Similar overnight and weekend restrictions have been reported further west along Highway 40 near Vaudreuil, part of the same seasonal maintenance push by Transport Québec across the greater Montreal region. If your commute regularly crosses more than one section of the A-40, it’s worth checking Québec 511 for the full corridor, not just the Repentigny listing, since overlapping closures on the same night are possible during peak construction season.
How to check real-time conditions before you drive
Traffic cameras and Québec 511 updates
Québec 511 is the best source for confirming whether the Repentigny closure is active, extended, or lifted early. The site and its mobile app update closure listings directly from Transport Québec’s work orders. For a visual check, WeatherBug’s Repentigny traffic camera feeds offer on-demand views of local road conditions, useful for confirming detour traffic volume before you commit to a route.
What to do if the closure extends past 5 a.m.
Overnight road work occasionally runs past its scheduled end time if crews hit delays. If you’re planning an early departure around 5 a.m. on August 19, check Québec 511 again before you leave rather than relying on the originally posted window. If the closure is still active, the same L’Assomption detour and local Repentigny and Charlemagne routes remain your fallback until Transport Québec updates the listing to show the highway reopened.
Frequently asked questions
Is Highway 40 open right now in Repentigny?
Outside the scheduled August 18-19, 2026 overnight window, Highway 40 in Repentigny operates normally. To confirm current status at any given moment, check Québec 511’s live conditions page, which updates closures and clearance restrictions in real time.
What is the detour for the Highway 40 closure this weekend?
For the August 18-19 overnight closure, expect traffic diverted through L’Assomption via Route 138, with local Repentigny and Charlemagne streets like Boulevard Iberville and Notre-Dame serving as additional alternatives for drivers who know the area.
Why is the clearance height reduced to 4.3 meters?
The 4.3 meter restriction points to work on a structure spanning the highway during the closure window, likely a sign gantry, overpass, or similar overhead element. Vehicles taller than 4.3 meters need to use an alternate route regardless of whether the main lanes are open.
Are there other Highway 40 closures planned in Quebec this month?
Yes. Beyond Repentigny, similar overnight and scheduled closures have affected the A-40 corridor further west near Vaudreuil this summer, part of Transport Québec’s broader seasonal maintenance schedule across the Montreal region.
How can I get live updates on the Highway 40 Repentigny closure map?
Québec 511’s website and mobile app show the live closure map with current restrictions, including start and end times and clearance height notices. WeatherBug’s Repentigny traffic cameras add a visual check for anyone who wants to see detour traffic conditions before heading out.
If you’re driving through Repentigny overnight on August 18, build your route around Québec 511’s live map rather than memory of the posted schedule. Road work windows shift, and a five-minute check before you leave beats finding a closed highway at 11 p.m. with no detour plan.