First of all, rallies are staged on public roads, not on a track. Rally cars navigate individually on the route, not wheel-to-wheel. And each team features a driver and at least one co-driver (navigator).

Rallies come in two main flavors: "TSD" and competitive. Competitive rallies are full-on speed events such as the Paris-Dakar rally. The Alcan rally is a TSD rally. "TSD" stands for "time-speed-distance." You win a TSD rally by driving precisely over the route, not just by driving fast.

TSD rallies are also called "road rallies."

Rallies are divided up into "stages" (or "sections") and "transits." Stages are where cars compete. Cars arrive at a checkpoint at the beginning of the stage, and are sent off down the stage at regular intervals (usually a minute apart). Each car's precise time of departure is recorded by the checkpoint crew.

In a competitive rally, the driver now tries to drive the unfamiliar road as fast as possible. The co-driver keeps the car on course by reading directions from a route book. In a TSD rally, the driver now tries to drive the unfamiliar road as _precisely_ as possible, maintaining the speed prescribed in the route book.

The stage has a checkpoint at its end (and TSD rallies often have several unannounced checkpoints along the way). These checkpoints record the precise time each car passes.

In a TSD rally, the actual time your car passed the checkpoint is compared to the time you _should_ have passed. If you are early or late, you accrue penalty points. At the end of the rally, the team with fewest points wins.

Some TSD rallies are also "course" rallies: the route book instructions are deliberately rigorous or tricky to understand correctly. The Alcan rally is generally not that way; it is a "tour" rally, where the challenge to competitors is to keep the brisk pace and execute the directions, no matter what the weather (raining, blizzarding) or situation (flat tire, carsickness, fatigue).

A TSD rally seems simple: Drive for 15.3 miles at 45 mph, turn left, now drive for 2.6 miles at 38 mph. But the reality is that nothing ever goes according to plan. TSD rallies challenge cars and tires to be utterly dependable, and drivers and navigators to be resourceful when the unexpected happens.