Published: August 4, 2014; updated: October 27, 2014
A slalom is in its most basic form a bunch of cones laid out in a row. The idea is to drive on the left of the first cone, then on the right of the second cone, then on the left of the third code, and so on until the end.
The basic version of a slalom has cones laid out in a straight line with equal spacing:
An offset slalom typically uses two rows of cones like this:
Depending on which side the slalom is taken, an offset slalom is "easier" or "more difficult" than a straight slalom.
The spacing between cones may be increasing or decreasing. Increasing spacing prompts for increasing speed toward the end of the slalom, and decreasing spacing prompts for decreasing speed toward the end.
A slalom may also be laid out in a turn, which makes it similar to an offset slalom in that one side becomes more open while the other side becomes tighter.
The main purpose of a slalom usually is teaching looking ahead. "Looking ahead" in this context means looking not at the cone immediately ahead of the car, but at the second or third cone out from where the car is.
At lower speeds, a driver looking further ahead typically has smoother lines and makes fewer speed corrections through the slalom compared to a driver who is looking at the cone immediately approaching. Drivers looking further ahead are often able to driver through the slalom faster. Vision is even more important in slaloms with decreasing cone spacing or ones with offset cones.
Slaloms are a good way to introduce drivers to the feeling of lateral weight transfer. A slalom packs a lot of direction changes into short distance; as the driver increases speed, the weight transfer will be more and more pronounced.
When used in street driver training programs like Tire Rack Street Survival, slaloms are also employed to make drivers exceed lateral grip capabilities of their vehicles and observe resulting vehicle behavior. Increasing speed through the slalom changes a vehicle attitude from easy compliance to forced compliance (the driver must exert substantial effort to keep the car on course) to non-compliance. Both forced compliance and non-compliance are valuable situations to experience.
Finally, slaloms demonstrate the need for rhythm and setup. This applies more to competitive driving - typically autocrosses. Slaloms are meant to be taken at a constant speed; starting slow and speeding up wastes time in the beginning, and overspeeding wastes time when the driver has to brake to fit into the course. By "setup" I mean the difference between the trajectory that a vehicle travels and the driver inputs necessary to achieve this trajectory. Despite the line being farthest away from the cones in the transverse dimension as the vehicle passe the cones, driver must have applied steering input toward the center line of the slalom significantly earlier - there is a delay from when the driver starts to turn the steering wheel to when the steering wheel faces inside the slalom to when the car actually starts to face inside the slalom. In practice, drivers run the equivalent of a late apex line, turning into the course shortly after passing a cone, rather than in the midpoint between corners.
These are things that an instructor can do to help drivers in a slalom get more value out of it.
When I was autocrossing I would tape the bottom of my windshield to force myself look up, and consequently further ahead. I apply the same reasoning to the slalom except I use my hand to block the bottom of the driver's view. I typically put my hand just on the top of the dashboard. Depending on driver's seating position and the car, resting the hand on the dashboard can work well, or lifting the hand a bit higher may be best. I often need to move my seat forward to be able to get my hand over the dashboard in front of the driver.
Pointing At Cones
As we go through the slalom I would vocalize which cone I want the driver to look at, and point to it. Usually this is the second to third cone away from the car.
Asking Driver To Call Out Cones
Ask the driver to say "next cone" when they change which cone they are looking at. Some drivers will say "next cone" when the previous cone disappears around the hood of the car. Some drivers will be looking at 1-1.5 cones out (that is, sometimes they would look at the cone right in front of the car, and sometimes one cone further. Both of these drivers can be identified by when they announce the next cone. I try to have the drivers look 2-2.5 cones out at all times.
In a tightening slalom have the driver gently ease off throttle in the middle of the slalom, so as to maintain a rhythm through the entire slalom. Then have the driver apply brakes as they are getting to the tighter portion, if there is a clear transition. Some drivers would naturally favor one way of driving - have them try he other way.
Try accelerating out of an opening slalom, or a slalom which has empty space beyond it. The idea here is to line the end of the slalom with the "straight" following the slalom - effectively, another vision exercise.