Know When Traction is Poorest

What if traction is poorest just when you need it? Your ability to control your vehicle could be quite different than what you expect.

Sometimes when it's raining, you can't see ice on the surface of the road. Sometimes, a skiff of snow is really a thin disguise for ice.

How good will your tires grip the road? How can you be certain that you have traction?

How about making a test? That's exactly what I do.

So, let's see how to conduct a traction test to determine when traction is poorest, and when it's adequate.

A word of caution - don't try this unless you're confident you can recover from a vehicle that may go out of control for a moment. When in doubt, use some other testing method.

Testing for Traction

Select a straight and level portion of road with no vehicles around you in any direction. Travel at a speed that seems a little slower than necessary for apparent conditions because your test will help determine actual conditions.

The way I perform a test for traction is to first quickly and lightly apply the brakes for just a moment to see how the vehicle responds.

Doing it quickly will allow the wheels to regain tracking in the event that they lose traction and start to slide. Applying the brakes lightly will give me an idea of how the front tires are gripping the road since they do most of the stopping.

If the front wheels lose traction, that tells me that traction is poorest and I need to slow down even more from my current "test speed."

In the event that my front tires grip the pavement satisfactorily, I repeat the process using a bit more force on the brake, but applying the brake for only a moment. If subsequent testing shows satisfactory traction, I'll apply the brake for a bit longer as well, but always ready in an instant to release the brake should I detect sliding.

Making about 4 or 5 of these tests is sufficient to determine when traction is good or when traction is poorest. They can also be made periodically while traveling to verify traction when you suspect that conditions have changed.

Be mindful that I never slam on the brakes and hold them there to cause the vehicle to lose traction. This is dangerous, so don't think that such radical action is part of the test.

Estimate Safe Speed

Using this traction testing technique, I estimate the speed that is safe to travel in order to provide sufficient traction to stop my vehicle (the most important capability, followed by steering). The estimated safe speed takes into consideration that the tests were made at a slower "test speed."

If all tests show adequate traction, I travel with confidence at speeds a little greater than "test speed." If after sharp and prolonged braking the vehicle loses traction, I drop my speed of travel to well below the "test speed."

There is no formula for estimating a safe speed when traction is good or when traction is poorest. My only recommendation here is to be mindful of traffic and visibility as these have as much to do with establishing a safe speed as the grip your tires have on the road.

Done with Traction is Poorest, back to Safe Driving