Montreal is the biggest city in Quebec, and being the second metropole of Canada in term of population. It is also a well sprawled city with suburbs sprawling on about 100km in several direction from its Downtown.
Montreal is also an incontrovertible city for every travellers as all the highways and main routes goes through its urban centre, which is an island and one of the rare crossing point of the St-Lawrence. With a population over 3 millions and only few bridges, traffic jam are pretty common. It usually takes up to about an hour to cross the city from one point to another when the traffic flow is smooth and obviously certain industrial spots (especially along 'Boulevard Metropolitain' in Dorval Airport Area and along the A-40 in 'Montreal-Est') are to avoid being stuck.
Certain specific spots in the urban area, mainly nearby the metro station are well known for car-sharer and would be a perfect starts to leave the city. A sign marking the city you are heading to will always lower your waiting time, and will more surely help you getting a lift out of the island by a commuter faster.
You can walk north from the metro station Longueuil and find the bridge crossing the highway to join the A-15 in direction of the New York State/USA. It's probably not 100% legal to stand on the good spot there, but you will probably quickly get a ride.
A legal alternative is to catch the southbound A-15 traffic coming off the Pont Champlain (bridge). Theoretically, you could take Bus #14 from the Longueuil bus station to the Brossard area. Tell the driver you want to get off at Boulevard Marie-Victorin. For a reference point, look up the intersection of Place Turenne and Boulevard Marie-Victorin.
Because of the speed of traffic, you will want to hold a large, visible sign. Some suggestions: "NEW YORK" or "PLATTSBURGH, N.Y."
Border Crossing: Champlain-Lacolle (New York)
A note about the main crossing at A-15 known as "Champlain-Lacolle". It's technically illegal to hitch south from the main crossing as it is an Interstate highway on which pedestrians (including, er, especially hitchhikers) are forbidden. So unless you get a through ride across the border, there are some alternative border crossings to consider other than the main Champlain-Lacolle crossing on A-15 (I-87 on the U.S. side).
Alternatives to Champlain-Lacolle (A15/I-87)
Overton Corners (US), 6 km south of the village of Lacolle, is a small crossing mostly used by locals and by those in the know. It connects the Quebec route 221 with NY-276 and is about 2 miles east of the main Champlain-Lacolle border crossing that connects A-15 and I-87. Obviously, it's only useful if you can get a lift near there, but is sometimes worth saving the hassle as border guards from both countries are generally more laid-back here.
Other alternatives include Rouses Point, N.Y. and a crossing that links Hemmingford, Quebec and Mooers, N.Y. Both are a bit off the beaten path, but you can get a lift on US-11 back to I-87 pretty easily and you're well on your way. All of these places can easily be found on a map.
Southeast toward Burlington, Vermont (provincial 133)
If you want to get to the border at St-Armand, Quebec and the state of Vermont, you will have to get a bit outside of the island of Montreal, first, since most of the highways within Montreal directly lead into the highway that goes to the border of New York State. Crossing the border with New York, by hitchhiking, but especially on foot, is not recommended.
The best way to get onto the correct highway for the Vermont border is to take the St-Jean sur Richelieu bus 96 from the Bonaventure Metro Station (Le 1000 de La Gauchetière Terminus, follow the signs from within the Metro Station), all the way to the last stop, Terminus D' Autobus Saint-Jean, St-Jean sur Richelieu. The bus will cost about $8 CAN(they may have just changed the fare, website and signs say $9.20 CAN but the driver said $8) and you must pay the exact fare in cash. The bus runs 7 days a week, and a schedule in PDF format is here, if you click on the link "Circuits 96...".
Southeast toward Sherbrooke (A-10)
To access the A-10 highway from Montreal, you can go to the Panama bus Terminal in Brossard and walk to the A-10 (10 minutes walk) from there. To reach the Panama terminal from Montreal, you have to take the bus 45 at Bonaventure metro station (orange line). There are also other buses going to Panama terminal from that metro station - bus 45 is the most common. There are also buses coming from Longueuil metro station going to Panama Terminal. From the Panama Terminal, you have to walk south on Taschereau boulevard till you pass under the A-10. Then take the ramp on your right to get on the highway. Note that it is illegal to hitchhike direclty on the highway. This area might be equipped with security cameras which serve to notify provincial police of any irregularity.
East toward Quebec city (A-40)
There are a few ways to start hitching towards Quebec from Montreal by A-40, none of which easy, unfortunately. The most accessible place, if not very convenient, is on the corner of Cremazie and St-Hubert, which is not very far from Cremazie metro station, on the orange line. There is a light there just before the highway ramp. It works best when the traffic is heavy and going slow (morning and late afternoon), because the red light lasts only about 15 seconds (which is little time to hop in).
From Radisson metro station, on the green line, you can take bus 20 to take you to the Repentigny terminal, totally east of town. There you can walk (5 minutes) north to the A-40 Highway. The bus ride takes about 45 minutes to 1 hour. Note that it is illegal to hitchhike directly on the highway, so you may want to hitch on a highway ramp.
Go to Longueuil Metro station and then take bus 81 or 82. Get out at the highway A-20 (Right after Lafrance street). You can hitch in one of the ramps right there or go to the next entrance by crossing the railroad and get walk near the industrial area (about 200m, corner of de la Province Street and Transcanadian Highway service lane).
West toward Toronto
Take bus 411 express (or 211 non-express) from Lionel Groulx subway station. From the terminus, continue walking westward (or take bus 251). Turn right on Saint Pierre St and head straight. Going to Toronto, you can hitch at the on-ramp of Highway 20, after the underpass or walk the bridge and hitch directly on the road as it becomes a boulevard and there is plenty of space for vehicles to stop after the intersection, near the tourist information.
If you want to go to Ottawa, there's a great spot right before highway 40. Just continue straight past the 20 and along 'Avenue des Anciens Combattants' for about 10 minutes. For pictures of the spot, see: http://imgur.com/v2vDG and http://imgur.com/wPYQK
West toward Ottawa
Getting out of Montreal in that direction isn't easy. There are 3 strategies you might want to consider:
1. Go North toward the Laurentides with Highway 15 (see section below) until exit 31, then reach for Highway 50 / Route 148 heading West through Lachute, Papineauville, Thurso and Gatineau. A sign can be useful there, first to Mirabel and then "50". After that, the path is very straightforward. This route is especially useful if your final destination is Gatineau rather than Ottawa.
2. Take bus 221 express (or 211 non-express) from Lionel Groulx subway station as if heading to Toronto. At the terminus continue walking west (or take the 251). Turn right on Rue Saint Pierre and head straight. There's a spot right before highway 40. Just continue straight past the 20 and along 'Avenue des Anciens Combattants' for about 10 minutes. See pictures of the spot:  and .
3. Go West towards Toronto via Highway 20 (see previous section) and ask to be dropped at exit 17 - St-Clet / Coteau du lac. From there hitch on the 201 North, towards St-Clet. Next village is Hudson and there is a major service station and restaurant area on Highway 40 there. You'll usually get a direct ride to Ottawa.
North toward the Laurentides
Take the subway to station Montmorency. At the main exit, go left then right towards boul Lecorbusier. There is an on-ramp for Highway 15 direction North, although there isn't much space and there's a fair load of traffic, it is possible to hitch there. Technically it's not a legal spot as there isn't space before the highway sign, but it's still doable. Please contribute any other option you'd know in that direction.
Laval is a suburban city within the Montreal Metropolitan Area and an island located north of Montreal in Quebec. It follows the rule of being actually the only entity being it's own city, island, county and administrative region. This, even if its existence is pretty much dependent of the .
There are currently in Laval three subway stations linked to Montreal's network. Getting there can be done with a regular subway ticket, but there is a different ticket price if you get on the network from them.