Road closures for Montreal this weekend: La Fontaine Tunnel to close overnight Saturday
Posted August 5, 2025 1:39 pm.
Mobility Montréal advises road users that major obstructions are expected over the weekend.
Road users can expect a complete nighttime closure of Highway 25 in both directions, including the Louis-Hippolyte-La Fontaine Tunnel, will be in place during the night of Aug. 9 to 10. This obstruction is required to carry out work related to the tunnel’s electrical and communications systems, the installation of oversized vehicle detection cameras and for roadway work.
A complete closure on Highway 20 in the east direction is also planned during the night of Aug. 8 to 9 in order to carry out work on lighting equipment.
During the night of Aug. 9-10, teams will finalize the installation of detection equipment targeting oversized trucks, along Highway 25 northbound.
Night closures during the week
Highway 25 towards the South Shore
- Complete closure of Highway 25 towards the South Shore (including the Louis-Hippolyte-La Fontaine tunnel) between exit 5 (Route 138, Hochelaga Street, Sherbrooke Street) and the entrance from Île Charron, from Saturday 11 p.m. to Sunday 9 a.m.
- Entrances to this section will be closed 30 minutes before the motorway is fully closed.
- Souligny Avenue eastbound, between Dickson and Honoré-Beaugrand streets, will be closed 30 minutes before the full highway closure.
Highway 25 towards Montreal
- Complete closure of Highway 25 towards Montreal (including the Louis-Hippolyte-La Fontaine tunnel) between exit 90 (Highway 20 West, Route 132, La Prairie / USA , Varennes , P.-E.-Trudeau Airport) and the entrance from Sherbrooke Street East, from Saturday 11 p.m. to Sunday 9 a.m.
- Entrances to this section will be closed 30 minutes before the motorway is fully closed.
Highway 20 Eastbound
- Complete closure of Highway 20 eastbound, between exit 93 (Nobel Street) and the entrance from Montarville Street, from Friday 10 p.m. to Saturday 8 a.m.
Asphalting work on Highway 640 begins on Aug. 10
Quebec’s Ministry of Transport and Sustainable Mobility announced the start of paving work on Highway 640, between Highway 15 (des Laurentides) and Chemin du Bas-de-Sainte-Thérèse in Blainville, on Aug. 10.
This work will continue until the end of October. These interventions are primarily aimed at improving safety and driving comfort on this road.
Traffic management
Carried out mainly during the night in order to limit the impact on the road network, this work will result in partial and complete closures of sections of the highway and access ramps, between Highway 15 (des Laurentides) and Chemin du Bas-de-Sainte-Thérèse:
- Eastbound: Sunday to Thursday, 10 p.m. to 5 a.m., Friday, 11 p.m. to 7 a.m., and Saturday, midnight to 8 a.m.
- Westbound: Sunday to Thursday, 10:30 p.m. to 4 a.m., Friday, 10 p.m. to 7 a.m., and Saturday, 11 p.m. to 8 a.m.
The speed limit may be reduced in the construction area during closures. Work will be coordinated to minimize impacts and detour routes. During complete closures, detour routes will be marked with temporary signs.
In the event of adverse weather conditions or operational constraints, work may be cancelled or modified.
Before hitting the road, it is recommended to consult Québec 511.
