Following Distance

This is a question for those studying or in training.

Under normal interstate driving conditions, medium traffic, how much following distance should you try to maintain between your truck and the one ahead of you?

And how can you determine this without looking it up in a book or having to ask someone else?

The length of your vehicle plus 1 at speeds over 40? 53 foot trailer plus 15 foot tractor. 8 seconds would be my guess.

To determine this you count the seconds the vehicle in front as it passes a shadow or some type of land mark. The seconds it takes for you to cross the same land mark or shadow is your following distance

Ok, here is a neat method to make this particular determination. And I’ll use my truck in this example, although different makes might produce slightly different results. (I drive a Frightliner).

My top speed is 68 mph. If I’m on my cruise and I come up behind another vehicle going slightly slower (a shout out here to all the Prime drivers, lol), my radar will slow me down to the matching speed and keep me 350 feet away. And yes, my dashboard display tells me how many feet away I am. A truck being 70 feet long, this translates into 5 truck lengths. That’s a little over a football field in length.

And take weather and road conditions into consideration. My example of 350 feet might be too close in certain conditions. And in certain situations the distance might be less, but in that scenario I wouldn’t be using cruise control or else I would be on cruise at a lower speed, and my radar will keep me at a safe distance for the speed I’m at.

Everywhere I've ever worked taught a minimum of 6-8 seconds of following distance. If you can maintain that in medium traffic then do it--it's possible more than we think. Realistically, my rule is I want to make sure I can stop in time or get over if the car in front of me suddenly wrecks/stops/runs over something I can't see--pretty much ends up being a bare minimum of 4-6 seconds of following distance at any given time and it's also extremely important to always leave yourself an out.

What we were taught is 1 second for every ten foot of length of your combination.

So I guess if you're 70 feet long then 7 seconds space. If you are traveling above 45 mph, you must add a second, so 8 seconds space. You should increase this in rainy conditions & such.

The way to determine your follow distance is to take the car in front of you and watch as they pass an object on the side of the road, such as a sign, tree, bigfoot, whatever.

Then count in your head until you have also reached that object. That lets you know your follow distance for sure.

This is a question for those studying or in training.

Under normal interstate driving conditions, medium traffic, how much following distance should you try to maintain between your truck and the one ahead of you?

And how can you determine this without looking it up in a book or having to ask someone else?

As always; weather conditions, construction and traffic density require maintaining additional following distance.

No matter what the conditions are, if possible, I try not to “bunch” with other traffic, especially trucks.

Use common sense.

I use the Smith system, specifically always leave yourself an out. As Gtown said, I really try to avoid being bunched up with other traffic. Especially other trucks. Our trucks forward collision radar will beep incessantly if your too close, I aim to keep that from happening.

When I get the invariably close cutin in front of me, I just pre slow, you'll feel them coming in. I just roll off the throttle early and let the gap widen. Mostly it's cars that do it, but some trucks too. I think after a while, you develop muscle memory of how large of a gap to maintain. It should be based on sound fundamentals.