My advice for visitors who want to drive in Montreal is:
DON'T DO IT!
Really, it's probably not worth the headache.
We have a web of one-way streets that will make you crazy. Our infrastructure has been deemed worse than most of the Third-World's. Parking can be an expensive nightmare - also once you do find one, you better know how to parallel park and quickly!
We are speed demons on the road who will cut you off in a second, from the left or right. Stop signs are taken as suggestions. Yellow lights mean speed up and get through the intersection.
It is all a bit wild, but once you understand it, you'll see the chaos actually has a sense of predictability to it.
Many people here drive like they don't care if they get killed or kill you. If you're ok to take that chance, by all means, come play Russian Road Roulette with us.
On the plus side, we have an amazing extensive public transport system. The majority of our taxi drivers are decent, non-shady characters. We have wonderful sections of the city reserved purely for pedestrians and of course we have the largest underground city in the world.
Who needs a car in the city then?
I'll concede you do probably want a car to get out of the city, though our commuter trains are a very comfortable and affordable way to do that.
All that said, if you really are game to drive, there are a few things you should know:
All our road signs are in French. "Arrêt" means stop. "Congestion" means traffic and "bloqué" means the road/exit is blocked. Since we're under almost constant construction, you'll see lots of that, in addition to "detour." A "sortie" is an exit and an "Expy" is an expressway.
You can't turn right on a red light on the island of Montreal. Obey any restrictions for right turns on reds when off the island.
This tip is useful for all of Canada: even numbered highways run east-west and odd numbered run north-south. Flashing green lights give you priority turn priviledges.
You do not need to yield at flashing yellow lights. You need to treat flashing red lights as a stop sign.
At a four-point stop, the person on the right has the "right of way." I'll put this loosely though as much of the time, it goes by who got there first.
When you see a green arrow, you can go straight but NOT TURN unless it turns to a full green light or a turning arrow.
A sign with a black straight arrow means you cannot turn, you MUST continue straight, even if it would be theorectically possible. Don't anger locals or upset the flow of traffic by trying to get away with it.
There are some signs that prohibit turns during certain hours, usually during rush hours. They're in 24 hour time, so understand the system before you get on the road.
While there are exceptions, most Montreal drivers seem to be extra impatient with outside license plates. Don't take it personally. We have speed cameras, so you'll receive a bill in the mail if caught.
The secret to winter driving is to go SLOWLY. Don't stomp on the brakes either. Everything must be done with a light touch. Winter tires are obligatory on all vehicles from December 15th til March 15th, but Communauto is exempt.
Children up to 40lbs and 63cm must travel in an appropriate safety seat and never in the front seat. Taxis are exempt from this requirement.
Above all, use common sense, keep your eyes open and bring a bucket full of nerves and patience with you.
Good luck and happy driving!
Feel free to comment with other tips and experiences!