ONCE UPON A TIME .....
I calculated that if you get 10 cars driving down the motorway, all keeping 'Highway Code' distances, but reacting only to the car immediately in front, then if the leading driver just releases the 'gas' (i.e. doesn't even brake), the 10th car WILL hit the 9th.
THEN ....
(in a fit of pique following a 30mph speeding ticket on an empty rural road)
I decided to drive down a busy M4 at EXACTLY 70 mph. Was in lane 3 as there were a few vehicles in 1 and lane-hoggers in 2. (Must admit I didn't have a satnav then so I must have been doing only 67 - sorry everyone)
I waited til there were 8 'close followers' behind me in the mirror, then gently and momentarily took my foot off the gas, and watched ..... The last vehicle was definitely in distress - bonnet well-dipped. Then I drove on - with a slight conscience, I have to admit.
The motorway is not the best place for uncontrolled scientific experiments.
What happens - as some of you will know - is the 'Peloton' effect. (Look it up on Wikipedia, as half the world did during the Olympic cycling). There is elasticity in the group, and those nearer the back get a very raw deal.
Message:- keep a 2-second gap. If it's so busy so that this is difficult to achieve, then at least look well ahead, to anticipate changes in traffic and slow down without having to brake.
And if there is a 'gaggle' of close-followers ahead, leave a 'firebreak' gap so that you can deal more safely with any 'shunt' incidents ahead. Otherwise you'll eventually become part of one of those '3-car, minor injury, collisions' which hold everybody up on hot sunny motorway trips.
The 'victims' always look SO surprised that it has happened to THEM in their precious little 'first car'. And on police TV shows, their line is often 'the car in front braked too hard with no warning'.
YHBW (You Have Been Warned) !
For interest, watch YouTube "M6 Crash 22 Aug 2012" - caught on my 'black box' camera. No idea what actually happened, but it illustrates why full Highway Code stopping distance is a good gap to leave.
But the kindest thing to do in busy traffic is to keep up towards the speed limit if it's safe, keep a safe distance (Highway Code Rule 126), and be patient.
Nowadays we need to co-operate, not compete.
Maybe I should change my name to 'Notacompleteangel', though.