Officials are warning drivers to, "if possible," stay away from some areas ahead of what Mobilité Montréal describes as "major traffic restrictions" in the Montreal area this weekend, October 21 to 24.
The organization responsible for traffic management in the metropolis says the Louis-Hippolyte-La Fontaine Tunnel (Highway 25 toward Montreal), Highway 40 eastbound in the West Island, and the Saint-Pierre Interchange (Highway 20 and Route 138) are to be especially avoided.
Map of Montreal area highways showing areas to avoid during the weekend of October 21 to 24.Mobilité Montréal
Ahead of the planned three-year, three-lane closure inside the La Fontaine Tunnel beginning October 31, the entire northbound section of the tunnel will be closed from 10 p.m. Friday to 5 a.m. Monday. Traffic will be diverted to the Jacques Cartier Bridge.
The following week, only two lanes in each direction will be open in the tunnel. From October 31 to November 2025 (!) only one lane will be open toward Boucherville and two lanes will be open toward Montreal.
In the West Island, the eastbound section (i.e. toward downtown Montreal) of Highway 40 will be completely closed between exit 44 (boulevard Morgan in Baie d'Urfé) to the next onramp from the service road (about a 1.8-kilometre stretch) from 8 a.m. to 11 p.m. Saturday.
Thereafter, until 5 a.m. Monday, only one lane will be open in the same eastbound section.
The Saint-Pierre Interchange will be a jumbled mess. From midnight Friday (meaning 12 a.m. Saturday) to 5 a.m. Monday, the ramp from Route 138 to Highway 20 west will be closed. And beginning at 7 a.m. Saturday, the eastbound section of the 138 will be down to one lane in the interchange (and hence the entrance from rue Clément will be closed). The two other lanes will reopen at 11 p.m. on Sunday.
In Dorval, Highway 520 westbound will be closed between Exit 2 and Highway 20 (roughly 3.6 kilometres) from 8 p.m. Sunday to 5 a.m. Monday. There will therefore be no direct access from Highway 520 to Montreal-Trudeau Airport during that time.
Also in Dorval, one of three lanes of Highway 20 westbound will be closed between the Dorval Interchange and boulevard Fenelon between October 25 and October 31.
The complete list of traffic impacts, including local street closures and off-island closures, is online.