Metro and Buses
Montreal's metro system is clean, efficient, and covers the central city well with four lines and 68 stations. Each station was designed by a different architect, so the system doubles as an underground architecture tour. Trains run on rubber tires, making them remarkably quiet. The STM bus network fills in the gaps. An OPUS card with a day or weekly pass is the easiest way to ride -- load it at any metro station.
Service runs from about 5:30 AM until roughly 1:00 AM, with extended hours during major festivals when the metro sometimes runs all night.
BIXI
Montreal's bike-share system, BIXI, is excellent and widely used from April through November. Stations are everywhere in the central neighborhoods. A day pass is inexpensive and gives you unlimited 30-minute rides. The city has an extensive network of bike lanes, especially along the Lachine Canal, through the Plateau, and across the islands in the river.
Walking
The central neighborhoods -- Old Montreal, downtown, the Plateau, Mile End -- are very walkable and best explored on foot. In winter, the underground city (RESO) lets you walk 33 kilometers of interconnected tunnels between metro stations, shopping centers, hotels, and office towers without stepping outside.
Car
Driving in Montreal is not recommended unless you are leaving the city. Traffic is heavy, construction is perpetual, and parking is expensive and scarce. If you do drive, watch out for the aggressive lane changes and the no-right-turn-on-red rule that applies across Quebec.
Taxi and Rideshare
Taxis are readily available and reasonably priced. Uber operates in Montreal. Both are useful for getting home late at night or reaching neighborhoods not well served by metro.