It is the only secondary road whose route crosses the Island of Montreal.

North of the Autoroute 40, Route 335 splits to a one-way pair, following Berri Street southbound and Lajeunesse Street northbound, and then crosses the Viau Bridge over Rivière des Prairies to Laval.

Route 335 once followed the entire length of Laurentian Boulevard to the David Bridge on the Rivière des Mille Îles, but now concurrently with Autoroute 440 for about 1.5 km (0.9 mi) to Autoroute 19.

North of the bridge, the Route 335 once ran along Montée Gagnon from Route 344 northwards, but now follows the Autoroute 19 right-of-way along Louis-Joseph-Papineau Boulevard to Côte-Saint-Louis Road East (French: chemin de la Côte-St-Louis est).

There are plans to extend Autoroute 19 along Route 335 to Autoroute 640 in Bois-des-Filion with anticipated completion in 2027, with the first phase being 1.5 km (0.9 mi) extension and an interchange at Rue Saint-Saëns.