﻿ stopping distances   Phone and text number is O774 -765 -1161

info@ken-neal.co.uk  MPH

20     ______   ______  12M (40ft)

6M             6M

30    _________   ______________   23M (75ft)

9M                 14M

40    ____________   ________________________ 36M (120ft)

12M                      24M

50    _____________   _____________________________        53M (175ft)

15M                         38M

60    _________________   _____________________________________  73M (240ft)

18M                               55M

70   _____________________   __________________________________________  96M (315ft)

21M                                         75M

The stopping distance will be doubled (x2) when the roads are wet and multiplied by ten (x 10   times)   when the roads are Icy and snowy.

Below is a chart showing a system for working out the overall stopping distance in feet.

Example: 30mph x 2 ½ = 75ft

Thinking distance in feet is the same as the speed you are travelling at.

Example: 30mph = 30ft thinking distance.

To calculate the braking distance in feet just deduct the thinking distances from the overall   stopping distance.

Example: 75ft – 30ft = 45ft.

Calculation for stopping distance in feet

MPH  Thinking distance  +  Braking  =  Overall stopping distance  =  MPH x?

20                 20                +      20       =                  40                           =  20 x 2

30                 30                +      45       =                  75                           =  30 x 2 ½

40                 40                +      80       =                  120                         =  40 x 3

50                 50                +     125      =                  175                         =  50 x 3 ½

60                 60                +     180      =                  240                         =  60 X 4

70                 70                +     245      =                  315                         =  70 x 4 ½

Separation Distances

A reasonable rule to apply with good dry roads conditions is a gap of 1 metre per MPH of speed.

Example: 45 MPH = 45 metre gap.

To judge this gap a useful technique is the ‘two second rule’. When the vehicle in front passes an   object, say to yourself – ‘only a fool brakes the two second rule’ or one Mississippi two   Mississippi’ if you reach the object before you’ve finished saying it then you are too close.

If a vehicle travelling behind you has a gap of only 1 second, then you will need to increase the

gap in front of you to 3 seconds.

____ Thinking Distance

____ Braking Distance