Can you tell exactly how long it will take you to stop in an emergency situation, how much distance you will need?
Nothing irritates me more than to have some idiot right on my bumper so close that he or she has can see the tiny scratch on the tailgate of my pickup. I just want to pull over and let them either drive by, or force them to stop. Don't they know this is not safe for me or for them? I know a guy who was just driving home in his neighborhood and a young girl behind him rammed him as he turned into his driveway because she was following too close. I know another guy who had to stop when a kid ran out in front of him and the man behind him plowed into him because HE was too close. But it's not just in town. I see people tailgating out on the highway! You've probably heard all kinds of stories about this. Can you give some advice?
Time to go back to driver's ed, Dale.
The Oklahoma Driver's Manual says: “You should always give yourself a ‘cushion of safety,' having open space in front, behind and on the sides. Avoid following too closely. Stay far enough behind the next vehicle that, if it should stop suddenly, you can stop safely.”
The manual says you should allow one car length for every 10 mph of speed, or, use the “two-second rule.” That means selecting “a fixed object, such as a tree, roadside sign, or utility pole ahead of the car in front of you. Once the car has passed the object, you should be able to count, ‘One thousand one, one thousand two,' before you pass the same object. In bad weather or poor road conditions, increase your count to four seconds (one thousand four).”
And remember, trucks take longer to stop because of their size, if nothing else. A truck may have better traction on wet roads or at higher speeds, meaning you may be rear-ending the truck if that happens.
Depends on variables
Back to the question ... the answer is: no. There is no way to tell exactly. It depends upon variables such as your reaction time, affected by your activity while driving; weight of the vehicle, including load; tire type and condition; weather; road conditions; and brake conditions.
Dale's frustration is shared by many — including yours truly — who find themselves followed so closely that a sudden stop would be almost a guarantee of a collision. The tailgater may be young or old, male or female, but certainly not making an intelligent decision.
The driver's manual says there are three steps in stopping your vehicle — perception, reaction and braking.
It takes about half a second to see or hear danger. That is perception. Reaction time, at best, is about .66 seconds. That's when the brain tells the foot to brake. The braking/stopping time depends on the speed. That's when you press the brake pedal until the vehicle stops.
Remember I said there is no way to tell exactly how long and how much distance it will take you to stop? Well, there are estimates, based on tests and analysis.
Numbers against you
Here, from the manual, are estimated emergency stopping distances (“from eye to brain to foot to wheel to road”) for various speeds. The first number is driver reaction distance, the second is braking distance and the third is total stopping distance. Please read carefully:
20 mph — 44 feet, 15-22 feet, 59-66 feet.
30 mph — 66 feet, 33-50 feet, 99-116 feet.
40 mph — 88 feet, 53-107 feet, 141-195 feet.
50 mph — 110 feet, 83-167 feet, 193-277 feet.
60 mph — 132 feet, 120-240 feet, 252-372 feet.
70 mph — 154 feet, 163-327 feet, 317-481 feet.
80 mph — 176 feet, 213-427 feet, 389-603 feet.
The numbers are against you.
By the way ...
If someone is following you too closely, flash your brake lights, if braking will not cause a collision; slow down and encourage the driver to pass; stop and let the tailgater go by. The manual recommends keeping your doors locked and stop in an area where there are other people. If it's dark, pull into a well lighted area.
Enjoy your week and drive safely.