So many traffic accidents happen when we don’t keep our proper distance from the cars in front of us. Here’s a simple equation to help you do just that:
Distance (in car lengths) = (Speed/10) – 1
Let me explain it. Say you’re going along at 20 mph — the distance between your car and that in front of you should be 1 car length. If you’re going along at 40 mph — the distance between your car and that in front of you should be 3 car lengths. Obviously, the formula given above is no good at speeds below 10 mph, so use your judgment there. I try to leave half a car-length to 1 car length between my car and someone in front of me, even if my speed is fairly low. I never know when they could brake suddenly. People’s actions can’t be predicted, and it’s best to have a little room for error in our calculations and reflexes.
I would go further and add an additional car length to that distance — in other words, modify the equation as follows, if you’re older and have problems seeing, if it’s dark, or if it’s rainy or foggy.
Distance (in car lengths) = (Speed/10)
If it’s snowing or it’s icy on the roads, by all means, drive slower and keep as far away from the car in front of you as you can. There’s no way to approximate distances in those situations. You never know just how your car will behave when you brake. Just hope you don’t have to brake on a particularly icy portion of the road, because you’ll skid all over the place, and chances are you’ll hit something.
One additional word of advice. If you’re going to drive through snow, sleet or ice, make sure you’ve either got winter tires on your car, or you’ve got good all-season tires that aren’t worn out. And be sure that your brakes are in good working condition.
I don’t claim to be a traffic safety expert, so don’t think this rule of thumb is written in stone. See how my advice will work for you, and let me know if you think my equations need some adjustments. The idea is to keep the math simple so that everyone can understand and benefit from this.
Discover more from Raoul Pop
Subscribe to get the latest posts sent to your email.
Raoul Pop 
Try as I might to leave a safe distance, it seems someone inevitably cuts in front of me. At 70 mph the distance between cars needs to be pretty far, but apparently most people don’t understand the concept. Thanks Raoul for posting this. If one person reads this and realizes they need to back off, I’m happy.
LikeLike
Here in South Africa the rule for many years has been to maintain a minimum of a three second gap. This can be estimated by starting to count “One thousand and one, one thousand and two” as the car in front passes a landmark. If you pass the landmark before reaching “One thousand and three”, you’re too close. If I recall correctly this started back in the 1970s or early 1980s and was a simpler way of calculating following distance without having to take varying speed into account. There was even a test section of highway with arrowheads painted in the lanes, spaced such that if you could see three of them between yourself and the car in front, you had a big enough following distance.
This following distance is for dry road conditions with good visibility and should be increased for wet roads or in poor visibility. Snow driving is fortunately not something we have to contend with much, as even rainy conditions are too much for the average South African, who has a notorious disregard for the rules of the road.
LikeLike
Coming from a region in Germany where we know snow here are some simple rules:
– Don’t believe all-wheel drive makes you brake any better or will do miracles if you take a corner too fast
– Same goes for ESP or whatever your car maker calls their stability program
– As you already noted: get winter tires! If you don’t and you’re the one in front of me crawling up that steep hill, better make sure you can run really fast!
– Turn on your lights. DON’T turn on your flashy fog lights just because you can. Especially those bright lights on the back can be really distracting for the person following you.
– Go to a large snowy place (parking lot or something) where you won’t be able to destroy anything and learn how your car reacts. Especially how much further you’ll go on snow while braking.
– Don’t slow down the whole traffic just because you’re seeing snow on the side of the road for the first time of your life — it will only make people angry and they might do stupid maneuvers trying to overtake you.
I know there are many more to add, but these are the first that came to my mind. Good idea Raoul, I guess I’ll post more to my blog sooner or later…
LikeLike