Quote:
Originally Posted by actwithclarity
It would take 0.123 seconds to travel 10ft at 55mph. However since a truck cannot stop instantly (lol), saying you only have that long to react is kind of dumb. The main concern is you have to be able to decelerate faster than the truck. I know my little geo metro has pretty weak brakes, so if a trucker really slammed on it I don't know if I'd survive that.
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Calculate your gap by doing the following:
When the back of the truck/car in front of you passes an object like a road sign, start counting till the front of your car passes the object.
At 10' back on the highway, you can't even begin to count as only .1 second will go by. That is WAAAY to close for anything but a closed race track. There are too many variables on the open road and everyone may have to slam the breaks without warning at any time.
A "safe" following distance per drivers ed is 2 seconds back. I push that a bit to get a better draft down to say, 1 second and only if it is a big rig since they don't stop as fast as passanger cars which adds just a little buffer. I won't get any closer than that. At 55 MPH, you are going 75 feet per second so that is how far back you would be.
At 75MPH you are going 100 feet per second. If you are 100 feet off the back of the next car. That sounds far but you still get a good amount of pull from 1 second back. Any closer than that will put you in a very dangerous position.
Using this method, your gap becomes more and more as you drive faster to give yourself the same amount of time to react reguardless of your speed. Easy way to draft and at the same time keep your risk to a minimum.