Scameras breach of faith

However, some of us consider that this is too little. If the vehicle in front stops dead, perhaps as a result of hitting something solid, a two second gap may be insufficient at high speeds or if the road is wet or icy.

In particular the authorities recommed doubling this time on wet roads.

A modern car can perhaps lose 20mph per second under emergency braking on a dry road. So at 70mph you would require 3.5 seconds to stop, plus perhaps a second for thinking time if you are paying attention. buttuming uniform braking you would have 4 seconds to stop before colliding with the vehicle in front. It doesn't take much inattention does it?

So, if you prefer to have some safety margin in hand, so that you can stop without using maximum braking and perhaps avoid being rear-ended by the tailgater behind you, it is better to double the distance anyway, then add a second for thinking time. Hence the 5 second rule.

At higher speed of course, a longer gap is appropriate.

To estimate you gap, just add to the two second rule estimeate by saying to yourself

"Only a fool breaks the two second rule, the three second rule, the four second rule, the five second rule" as appropriate for your speed. You will soon learn to judge the distance without doing this,

And in case you think it can't happen, two weeks ago a vehicle in front of me did stop dead after hitting a pile of crashed HGVs on the M1. The 5 second rule may have saved my life, along with those in the vehicles following me.

The Highway Code gives stopping distances, but im my experience it is much easier to estimate time than to estimate distance.

Martin

-- Created on the Iyonix PC - the world's fastest RISC OS computer.