24-07-2021, 04:56 PM
(This post was last modified: 24-07-2021, 05:20 PM by Reckless Rat.)
Overall stopping distance in the Highway Code is thinking distance plus braking distance, hence the 23m at 30mph.
The thinking distance is based on distance travelled in 0.7 secs relative to the speed. The speed in mph being the thinking distance in feet, eg, 20mph, 20 ft, 30mph, 30 ft, etc.
This means that the 23 metres quoted should have the thinking distance deducted to give the braking distance, which is 45 feet at 30mph, or 13.7 metres.
Braking distance is calculated as speed squared divided by 20, so in miles per hour and feet it is:
20mph 20ft
30mph 45 ft
40mph 80 ft
50mph 125 ft
60mph 180 ft
The thinking distance is based on distance travelled in 0.7 secs relative to the speed. The speed in mph being the thinking distance in feet, eg, 20mph, 20 ft, 30mph, 30 ft, etc.
This means that the 23 metres quoted should have the thinking distance deducted to give the braking distance, which is 45 feet at 30mph, or 13.7 metres.
Braking distance is calculated as speed squared divided by 20, so in miles per hour and feet it is:
20mph 20ft
30mph 45 ft
40mph 80 ft
50mph 125 ft
60mph 180 ft