Stopping Distance Wrong?

315 ft with the thinking distance added. Take away this distance and yes a car doing 70mph will stop in 246 ft (approx) I'm sure a modern car could actually stop well inside this distance though. ;););)
 
I thought it was 315 feet at 70mph?


This used to be the MINIMUM stopping distance based on a driver being alert and the car being in very good mechanical condition.

As stated though, a modern car with the likes of ABS etc could possibly do it in less distance.
 
So the stuff following the 'Jerry can' at 70 mph will likely plough into it's engine under emergency braking situation - unless 'tis followed by an alert little pug.
I think the figures in the highway code are deemed correct for average tyres, on an average dry road surface with average condition brakes. Not much sense in being anything else really.
Highway code reckons at approx' 103 ft/sec it takes 246 feet from application of brakes to full stop.
Say average speed during braking to a stop 103/2 = 51.5 ft/sec, then 246 / 51.5 = 4.8 secs stopping time, losing on average 103 / 4.8 = 21.46 ft/sec/sec or 21.46/32.2 = 0.67g.

At 170 ft (Clarko's Porsche and Pug) braking distance, linear deceleration about 0.97g

https://www.gov.uk/guidance/the-hig...-advice-for-all-drivers-and-riders-103-to-158

Rule126.

the-highway-code-stopping-distances.jpg

-0-
 
what point is there in remembering or cramming numbers in feet how long a car would take to stop, for most people they wouldn't have a clue how long is 264 feet, so why bother with that, when you have driven a car all your life, you know how much distance it will take to stop at any speed for that matter but certainly not in feet or yards or meters, instinctively a good driver will know when to start braking even in emergency situation a good driver will know his car won't be stopping in the given distance he can see so he may try to avert the accident some other way like veering away from the obstruction.

I know this will sound silly, but is true, when my driving test examiner explained to me that when he lifts his clipboard or note pad and slaps it on the dash of my car he would like me to make an emergency stop, so my natural reaction was so fast that as soon as he lifted his pad up from his lap to strike the dashboard, I slammed my brakes and he went flying out of the windscreen! Oh yes in those days fastening seat belts wasn't allowed! a few onlookers gathered after the incident and applauded me that I managed stop my car just in time before I could run the poor guy over, what they didn't know the chap standing shocked in front of my car was the freshly ejected examiner! some thought he had hit my windscreen!
 
Last edited:
Back
Top