Highway code stopping distances
Discussion
Does anyone know if, and when, stopping distances have been updated for the current Highway Code?
For instance; 70mph shows 21m/75m or 96m/315ft overall.
I'm afraid to say that I don't remember from my last reading of the HC, which may have been in Olde Worlde Saxon but 315ft is vaguely familiar.
If they haven't, should they?
For instance; 70mph shows 21m/75m or 96m/315ft overall.
I'm afraid to say that I don't remember from my last reading of the HC, which may have been in Olde Worlde Saxon but 315ft is vaguely familiar.
If they haven't, should they?
They haven't been updated in the last 16 years. I did my IAM in 1995 and memorised the stopping distances for that.
I'm not sure they are very relevant, even if they were accurate - who would recognise 315 feet while actually driving at 70mph?
I seem to recall Top Gear or 5th Gear showed a modern car accelerate from 0-60 and back to standstill in less than the highway code distance.
And these all do the 0-60-0 dash in under 7 seconds, but I don't know the distance they covered.
http://www.topspeed.com/cars/car-news/porsche-911-...
And more relevant to the real world, Top Gear's cheap car challenge comfortably beat the HC figures in their old bangers:
http://www.jeremyclarkson.co.uk/cheap-car-challeng...
I'm not sure they are very relevant, even if they were accurate - who would recognise 315 feet while actually driving at 70mph?
I seem to recall Top Gear or 5th Gear showed a modern car accelerate from 0-60 and back to standstill in less than the highway code distance.
And these all do the 0-60-0 dash in under 7 seconds, but I don't know the distance they covered.
http://www.topspeed.com/cars/car-news/porsche-911-...
And more relevant to the real world, Top Gear's cheap car challenge comfortably beat the HC figures in their old bangers:
http://www.jeremyclarkson.co.uk/cheap-car-challeng...
I had to go on a speed awareness course last year and this issue popped up.
The instructor guy said the stopping distances have not changed since the 60's when they were measured with some old Ford Anglia, and the same rules still apply today.
I tried to argue that my mrs car could stop quicker and safer than my 60's Beetle, and some ceramic disc super car could pull up quicker still. He had none of it. His argument was that modern cars are heavyr and ABS aids although wont lock up the wheels will add more to the overall stopping distance.
I was loosing the will to live at that point in the day and let him get on with things.
I'm sure the font of all car knowledge (Clarkson) did some sort of experiment where he stopped a car in half the space the highway code says.
The instructor guy said the stopping distances have not changed since the 60's when they were measured with some old Ford Anglia, and the same rules still apply today.
I tried to argue that my mrs car could stop quicker and safer than my 60's Beetle, and some ceramic disc super car could pull up quicker still. He had none of it. His argument was that modern cars are heavyr and ABS aids although wont lock up the wheels will add more to the overall stopping distance.
I was loosing the will to live at that point in the day and let him get on with things.
I'm sure the font of all car knowledge (Clarkson) did some sort of experiment where he stopped a car in half the space the highway code says.
irob said:
I had to go on a speed awareness course last year and this issue popped up.
The instructor guy said the stopping distances have not changed since the 60's when they were measured with some old Ford Anglia, and the same rules still apply today.
I tried to argue that my mrs car could stop quicker and safer than my 60's Beetle, and some ceramic disc super car could pull up quicker still. He had none of it. His argument was that modern cars are heavyr and ABS aids although wont lock up the wheels will add more to the overall stopping distance.
I was loosing the will to live at that point in the day and let him get on with things.
I'm sure the font of all car knowledge (Clarkson) did some sort of experiment where he stopped a car in half the space the highway code says.
Man, I wish I'd been there for that particular speech. I could have asked him what exactly qualified him to speak such complete bullsThe instructor guy said the stopping distances have not changed since the 60's when they were measured with some old Ford Anglia, and the same rules still apply today.
I tried to argue that my mrs car could stop quicker and safer than my 60's Beetle, and some ceramic disc super car could pull up quicker still. He had none of it. His argument was that modern cars are heavyr and ABS aids although wont lock up the wheels will add more to the overall stopping distance.
I was loosing the will to live at that point in the day and let him get on with things.
I'm sure the font of all car knowledge (Clarkson) did some sort of experiment where he stopped a car in half the space the highway code says.
t.Ozzie Osmond said:
Yeah, you may have good brakes but if the car behind hasn't then you've still had an accident!
That's a great excuse for the accident form - "I knew I had to stop but the guy behind didn't have as good a braking system as me so I didn't bother using mine properly".His brakes may be every bit as good as yours, but if he's changing the radio station, chatting to his passenger,thinking what to have for dinner, or whatever other reason he may not hit his brakes in the same timescale so the same result occurs.
You have mirrors so you can keep an eye on what is happening behind, too, and make plans to include that info.
Iain XR4i said:
Ozzie Osmond said:
Yeah, you may have good brakes but if the car behind hasn't then you've still had an accident!
That's a great excuse for the accident form - "I knew I had to stop but the guy behind didn't have as good a braking system as me so I didn't bother using mine properly".His brakes may be every bit as good as yours, but if he's changing the radio station, chatting to his passenger,thinking what to have for dinner, or whatever other reason he may not hit his brakes in the same timescale so the same result occurs.
You have mirrors so you can keep an eye on what is happening behind, too, and make plans to include that info.
te shopping trolley) wasn't going to stop in time (hilarious faces he and his wife were pulling) so I eased up on the brakes and pulled out and alongside the car infront in the central right-turn lane. The car behind ended up five feet from the car that had been in front of me. I think the bloke thought I was a tool but in reality it was intentional and saved me from a written-off car.McSam said:
an, I wish I'd been there for that particular speech. I could have asked him what exactly qualified him to speak such complete bullst.
I suspect there's no chance of arguing with this knacker. He'd have you by the stones and kick you off the course, resulting in those points you were trying to avoid. t.Reminds me of the film: anger management!
AFAIK, they haven't been updated since I did my cycling proficiency, which I think was 1983.
Thinking distance in ft = speed in mph
Braking distance in ft = speed in mph squared, divided by 20 (so divide by 2 and knock the 0 off).
Add the two together for overall stopping distance.
So:
30 mph = 30 ft thinking, 45 ft braking = 75 ft
40 mph = 40 ft thinking, 80 ft braking = 120 ft
50 mph = 50 ft thinking, 125 ft braking = 175 ft
60 mph = 60 ft thinking, 180 ft braking = 240 ft
70 mph = 70 ft thinking, 245 ft braking = 315 ft
Do these line up with the numbers in the current highway code?
Thinking distance in ft = speed in mph
Braking distance in ft = speed in mph squared, divided by 20 (so divide by 2 and knock the 0 off).
Add the two together for overall stopping distance.
So:
30 mph = 30 ft thinking, 45 ft braking = 75 ft
40 mph = 40 ft thinking, 80 ft braking = 120 ft
50 mph = 50 ft thinking, 125 ft braking = 175 ft
60 mph = 60 ft thinking, 180 ft braking = 240 ft
70 mph = 70 ft thinking, 245 ft braking = 315 ft
Do these line up with the numbers in the current highway code?
carl_w said:
AFAIK, they haven't been updated since I did my cycling proficiency, which I think was 1983.
Thinking distance in ft = speed in mph
Braking distance in ft = speed in mph squared, divided by 20 (so divide by 2 and knock the 0 off).
Add the two together for overall stopping distance.
So:
30 mph = 30 ft thinking, 45 ft braking = 75 ft
40 mph = 40 ft thinking, 80 ft braking = 120 ft
50 mph = 50 ft thinking, 125 ft braking = 175 ft
60 mph = 60 ft thinking, 180 ft braking = 240 ft
70 mph = 70 ft thinking, 245 ft braking = 315 ft
Do these line up with the numbers in the current highway code?
Yes they're all correct according to the Highway Code but in practice it would be interesting to actually see what they areThinking distance in ft = speed in mph
Braking distance in ft = speed in mph squared, divided by 20 (so divide by 2 and knock the 0 off).
Add the two together for overall stopping distance.
So:
30 mph = 30 ft thinking, 45 ft braking = 75 ft
40 mph = 40 ft thinking, 80 ft braking = 120 ft
50 mph = 50 ft thinking, 125 ft braking = 175 ft
60 mph = 60 ft thinking, 180 ft braking = 240 ft
70 mph = 70 ft thinking, 245 ft braking = 315 ft
Do these line up with the numbers in the current highway code?
We all know they are out of date but does it matter? They couldn't possibly publish a chart for all makes of cars on the road and their stopping distance.
They are but a guide, just remember "Only a fool breaks the 2 second rule".
Even if there was a chart for all cars on our roads, there would still be those gods who can not only claim be able to drive perfectly 100% in control with holding a phone to the ear, would argue thet could stop quicker.
We dont all drive super cars with Fangio instincts, I think if they did reduce the figures, some drivers would drive closer to those in front, maybe.
They are but a guide, just remember "Only a fool breaks the 2 second rule".
Even if there was a chart for all cars on our roads, there would still be those gods who can not only claim be able to drive perfectly 100% in control with holding a phone to the ear, would argue thet could stop quicker.
We dont all drive super cars with Fangio instincts, I think if they did reduce the figures, some drivers would drive closer to those in front, maybe.
carl_w said:
AFAIK, they haven't been updated since I did my cycling proficiency, which I think was 1983.
Thinking distance in ft = speed in mph
Braking distance in ft = speed in mph squared, divided by 20 (so divide by 2 and knock the 0 off).
Add the two together for overall stopping distance.
So:
30 mph = 30 ft thinking, 45 ft braking = 75 ft
40 mph = 40 ft thinking, 80 ft braking = 120ft
50 mph = 50 ft thinking, 125 ft braking = 175 ft
60 mph = 60 ft thinking, 180 ft braking = 240 ft
70 mph = 70 ft thinking, 245 ft braking = 315 ft
Do these line up with the numbers in the current highway code?
Another way to remember (And you can do this in your head) is that thinking distance is the same as the speed, ie at 70 thinking distance is 70 as we all now, to calculate the stopping distance is this, starting at 20, distance isThinking distance in ft = speed in mph
Braking distance in ft = speed in mph squared, divided by 20 (so divide by 2 and knock the 0 off).
Add the two together for overall stopping distance.
So:
30 mph = 30 ft thinking, 45 ft braking = 75 ft
40 mph = 40 ft thinking, 80 ft braking = 120ft
50 mph = 50 ft thinking, 125 ft braking = 175 ft
60 mph = 60 ft thinking, 180 ft braking = 240 ft
70 mph = 70 ft thinking, 245 ft braking = 315 ft
Do these line up with the numbers in the current highway code?
1 x 20, at 30 its 1 1/2 x 30, at 40 its 2 x 40, at 50 its 2 1/2 x 50 so on up to 70.
So to calculate overall stopping distance from 70 would be 3 1/2 x 70 = 245, plus the thinking distance of 70 gives you an overall distance of 315 ft.
Vipers said:
Another way to remember (And you can do this in your head) is that thinking distance is the same as the speed, ie at 70 thinking distance is 70 as we all now, to calculate the stopping distance is this, starting at 20, distance is
1 x 20, at 30 its 1 1/2 x 30, at 40 its 2 x 40, at 50 its 2 1/2 x 50 so on up to 70.
So to calculate overall stopping distance from 70 would be 3 1/2 x 70 = 245, plus the thinking distance of 70 gives you an overall distance of 315 ft.
or, just multiply the speed increments going up by .5. i.e.1 x 20, at 30 its 1 1/2 x 30, at 40 its 2 x 40, at 50 its 2 1/2 x 50 so on up to 70.
So to calculate overall stopping distance from 70 would be 3 1/2 x 70 = 245, plus the thinking distance of 70 gives you an overall distance of 315 ft.
30x 2.5 = 75
40x 3 = 120
50x 3.5 = 175
60x 4 = 240
70x 4.5 = 315
Iain XR4i said:
Vipers said:
Another way to remember (And you can do this in your head) is that thinking distance is the same as the speed, ie at 70 thinking distance is 70 as we all now, to calculate the stopping distance is this, starting at 20, distance is
1 x 20, at 30 its 1 1/2 x 30, at 40 its 2 x 40, at 50 its 2 1/2 x 50 so on up to 70.
So to calculate overall stopping distance from 70 would be 3 1/2 x 70 = 245, plus the thinking distance of 70 gives you an overall distance of 315 ft.
or, just multiply the speed increments going up by .5. i.e.1 x 20, at 30 its 1 1/2 x 30, at 40 its 2 x 40, at 50 its 2 1/2 x 50 so on up to 70.
So to calculate overall stopping distance from 70 would be 3 1/2 x 70 = 245, plus the thinking distance of 70 gives you an overall distance of 315 ft.
30x 2.5 = 75
40x 3 = 120
50x 3.5 = 175
60x 4 = 240
70x 4.5 = 315
I must have been thinking of those ladies amongst us who have no idea what 2.5 is, and that sir is my excuse, (Obviously a very very minority of ladies, like the one who couldnt work out how long it took to drive 80 miles at 80 mph)
Iain XR4i said:
... who would recognise 315 feet while actually driving at 70mph? ...
It's slightly (by 5 yards or 15 feet) longer than the distance shown by a 100 yard Countdown Marker approaching a roundabout or Motorway Sliproad 
. Not that testing your car's brakes in this fast-moving environment is recommended 
...As another poster has alluded to, this "stopping distance" was defined by testing in a Ford Anglia.
I could make comments about Harry Pothead and his ginger mate's Flying Car at this point, but can't remember what with the Ministry of Bewilderment & Denial Of Progress chasing me for brake testing on the approach to a roundabout on an A-road...
Joking, of course Iain XR4i said:
I'm not sure they are very relevant, even if they were accurate - who would recognise 315 feet while actually driving at 70mph?
Answer, not a lot, but at 70 the 2 second rule puts you about 205 feer behind the car in front, if I did my sums correctly, I am standing by to be told I fked up no worries. (difficult to focus sitting in 28 degres by the pool in Sydney)So maybe think at 70, "Only a fool breaks the 3 second rule"?
carl_w said:
AFAIK, they haven't been updated since I did my cycling proficiency, which I think was 1983.
Thinking distance in ft = speed in mph
Braking distance in ft = speed in mph squared, divided by 20 (so divide by 2 and knock the 0 off).
Add the two together for overall stopping distance.
So:
30 mph = 30 ft thinking, 45 ft braking = 75 ft
40 mph = 40 ft thinking, 80 ft braking = 120 ft
50 mph = 50 ft thinking, 125 ft braking = 175 ft
60 mph = 60 ft thinking, 180 ft braking = 240 ft
70 mph = 70 ft thinking, 245 ft braking = 315 ft
Do these line up with the numbers in the current highway code?
Oddly enough, these figures give a 2/3g deceleration, rod operated drum brakes anyone? Modern cars are nearer 1g...Thinking distance in ft = speed in mph
Braking distance in ft = speed in mph squared, divided by 20 (so divide by 2 and knock the 0 off).
Add the two together for overall stopping distance.
So:
30 mph = 30 ft thinking, 45 ft braking = 75 ft
40 mph = 40 ft thinking, 80 ft braking = 120 ft
50 mph = 50 ft thinking, 125 ft braking = 175 ft
60 mph = 60 ft thinking, 180 ft braking = 240 ft
70 mph = 70 ft thinking, 245 ft braking = 315 ft
Do these line up with the numbers in the current highway code?
Vipers said:
We all know they are out of date but does it matter? They couldn't possibly publish a chart for all makes of cars on the road and their stopping distance.
They are but a guide, just remember "Only a fool breaks the 2 second rule".
To be fair, I see them as totally irrelevant in any event and I would be astonished if any driver at all ever gave them a moments thought thought when driving. I do however find the 2 second rule ditty popping uninvited into my head from time to time. Mostly when I watch dimwits tailgating. I didn't think they had been updated and I'm not sure doing so would serve any purpose.They are but a guide, just remember "Only a fool breaks the 2 second rule".
Funnily enough my trail of thought leading to this thread was triggered by an impending speed awareness course (82mph on the M1). I fully expect stopping distances to be included and I wondered to myself if it was going to be a forum for debate or a lecture. My letter from the AA (seems they run the courses) says it is a 'discussion'. Will i be subjcted to a 4 hour evangelical sermon on the good book?
Like one of the posters above, I may find it difficult to sit and suffer in silence while b
ks is deliverd to a captive audience.We shall see, and I'm damm sure my car would stop within 315ft even from 82mph!
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