Beginning Monday, October 31, the Louis-Hippolyte-La Fontaine Tunnel between Montreal and the South Shore is partially closed to make way for a major renovation.

Only three of the six lanes inside the tunnel on Highway 25 are open: two towards Montreal and one toward Boucherville.

The partial closure is expected to last for three years, until November 2025.

Officials have been warning for months about the scope of the planned work on the tunnel and are encouraging commuters to seek alternate routes.

To draw drivers away from the tunnel, the Ministry of Transport and local transit authorities have made RTL bus lines 61 and 461, and exo bus lines 520, 521 and 532 free between so-called "incentive" parking lots on the South Shore and Radisson station on the green metro line in Montreal. There, until November 27, officials will be handing out free two-trip transit passes.

Five incentive parking lots are now free to use, three in Boucherville and one each in Beloeil and Sainte-Julie. Directions are online.

There's also the yellow metro line, which runs between Berri-UQAM station and its eastern terminus in Longueuil, where the ministry has vowed to increase bus frequency. There will also be an additional train running on the yellow line between 6 a.m. and 10:30 a.m.

One water taxi, between Boucherville and the Parc de la Promenade Bellerive in Mercier–Hochelaga-Maisonneuve, is free, too.

Other traffic mitigation measures are also on the table, including a proposal to limit the La Fontaine Tunnel to vehicles with two or more occupants.