By car

By car
Of course, many people choose to rent a car. Although somewhat expensive if you are travelling alone, this can be an economically reasonable alternative if you are sharing the costs with others. However, there are many limitations and drawbacks on car rentals in Canada. To name a few of them:
there can be very high surcharges associated with dropping off the car at a different location than where it was picked up.
Unlimited km are usually offered for the province you rent it in only. As soon as you enter another province, even for a few km, your entire trip gets limited (mostly to 200 km a day).
Driving is usually permitted on paved roads only.
There are no manual transmission rental cars available in Canada. Don't bother searching.
Basically said, if you really want to get around in Canada, except in Vancouver, Toronto, and Montreal, or places where there are few or no roads, it is best to have or buy your own car.
In some cases, frugal travellers may be able to "earn" budget automobile travel by delivering a car across Canada. The option is not common. Nor does it offer the opportunity to spent much time stopping along the way. However, it can be a cheap way to cross Canada while seeing the interior. CanadaDriveAway and HitTheRoad.ca are two options.
In Montreal, Toronto and Vancouver, public transit is a strongly recommended alternative to driving.
Gas prices are (May 2011) in the range of $1.30-1.40 per litre in most urbanized areas in the country, but that is typical and usually goes up in March, just in time for summer driving season. Year round, prices tend to be about 50% higher than those in the U.S. after converting litres into gallons and factoring in higher taxes and the currency exchange rate. American drivers will generally find that their credit and debit cards do not work in gas pumps in Canada (due to US cards generally not having "chip and PIN" functionality), although many of the larger chains (such as Petro-Canada and Esso) can run US cards via magnetic stripe if you bring the card inside to the cashier.
Of particular note is highway 407/ETR (Express Toll Route) in Ontario, which circles around the northern flank of Toronto. The 407 is an electronic toll road (the only privately owned road in Canada), in that tolls are billed to the vehicle's owner based on license plate number, or transponder account. Be sure to check your rental agencies' policy regarding use of this road as some firms have been known to add fees and surcharges that can easily double or triple the original toll.
Many jurisdictions also have red light and speed cameras that issue fines via mail to the car's registered owner, again via license plate when the car is automatically photographed running (disobeying) a red traffic light or going above the speed limit. The above warning regarding rental agency policies applies to these as well. Your best bet to avoid this nasty surprise is to simply not run any red lights or speed.