Stopping distances?
Discussion
Something I've always wondered is what car is/was used to measure the stopping distances that appear in the highway code and when was it done?
Did the car have ABS as most modern cars do, did it have huge front tyres / shiny Brembo's / 6 pot calipers with ventilated discs, or was it just a standard be-drummed ford escort?
Obviously newer and more advanced cars will stop far more quickly and safely than older non-assisted cars and I was just wondering if the distances are revised on a regular basis as technology and safety improves?
Did the car have ABS as most modern cars do, did it have huge front tyres / shiny Brembo's / 6 pot calipers with ventilated discs, or was it just a standard be-drummed ford escort?
Obviously newer and more advanced cars will stop far more quickly and safely than older non-assisted cars and I was just wondering if the distances are revised on a regular basis as technology and safety improves?
A quick Google found this about the BMW Z3 from a testing day:
But, to my amazement, the car came to a halt in 214 ft from 80 mph and only 118 ft from 60 mph
Highway code says:
20MPH (40 feet)
30MPH (75 feet)
40MPH (120 feet)
50MPH (175 feet)
60MPH (240 feet)
70MPH (315 feet)
Although not eveything stops as quickly as an M3, those distances are way, way out it's silly.
>> Edited by Muncher on Wednesday 18th February 19:39
But, to my amazement, the car came to a halt in 214 ft from 80 mph and only 118 ft from 60 mph
Highway code says:
20MPH (40 feet)
30MPH (75 feet)
40MPH (120 feet)
50MPH (175 feet)
60MPH (240 feet)
70MPH (315 feet)
Although not eveything stops as quickly as an M3, those distances are way, way out it's silly.
>> Edited by Muncher on Wednesday 18th February 19:39
Ive been thinking about this alot recently and the thing that got me going was the advert about the car that has to brake from 35 mph when the child/dummy figure is in the road.
From memory i think it said that the extra 5mph takes an extra 21ft?
Watching the advert the car seems to skid for along time and take a long time to stop(bearing in mind its in slow motion).
Ive tried snap braking from 30mph & 35 mph and my brakes/wheels dont lock like the advert,bearing in mind my car is a 13 year old Sierra and although it is highly maintained todays cars must out brake my car by a distance.
It leads me to think the advert is inacurate,has anyone else come to this conclusion.
From memory i think it said that the extra 5mph takes an extra 21ft?
Watching the advert the car seems to skid for along time and take a long time to stop(bearing in mind its in slow motion).
Ive tried snap braking from 30mph & 35 mph and my brakes/wheels dont lock like the advert,bearing in mind my car is a 13 year old Sierra and although it is highly maintained todays cars must out brake my car by a distance.
It leads me to think the advert is inacurate,has anyone else come to this conclusion.
ZR1427 said:
Ive been thinking about this alot recently and the thing that got me going was the advert about the car that has to brake from 35 mph when the child/dummy figure is in the road.
From memory i think it said that the extra 5mph takes an extra 21ft?
Watching the advert the car seems to skid for along time and take a long time to stop(bearing in mind its in slow motion).
Ive tried snap braking from 30mph & 35 mph and my brakes/wheels dont lock like the advert,bearing in mind my car is a 13 year old Sierra and although it is highly maintained todays cars must out brake my car by a distance.
It leads me to think the advert is inacurate,has anyone else come to this conclusion.
Would also suggest that if the numpty behind the wheel had learnt to drive properly, he would have pumped the brake pedal to avoid locking up the wheels for such a distance. Would therefore have stopped quicker and maintained better control of the vehicle to enable evasive manouvers to be made if necessary.
On the other hand, if it was a 4x4 driven at 20mph by a mum on the school run then the kid would be dead anyway.
ed up brake balancer!Highway code says 70-0 315 feet.... 68 feet is thinking distance 246 feet is braking distance, ignoring the decimal points(Highway code figures!)
Modern car, like a Boxster 161.9 feet of pure stopping.... Now if you are driving a highway code issue car, you are going to stop some 80 feet the other side!!! sheit
I know some kid shot out in front of me and nearly became a bonnet ornament. If I had been in my runabout Nissan, I know I couldn't have stopped!
On this basis, the government should be promoting performance cars for all on the basis of safety. Same driver, same reactions, but because I had the sense to drive a modern high performance sports car with big fat tyres and brakes one kid gets to live another day!!!
Modern car, like a Boxster 161.9 feet of pure stopping.... Now if you are driving a highway code issue car, you are going to stop some 80 feet the other side!!! sheit
I know some kid shot out in front of me and nearly became a bonnet ornament. If I had been in my runabout Nissan, I know I couldn't have stopped!
On this basis, the government should be promoting performance cars for all on the basis of safety. Same driver, same reactions, but because I had the sense to drive a modern high performance sports car with big fat tyres and brakes one kid gets to live another day!!!
mad jock said:
The ad in question is almost impossible to re-create in real life. The front wheels are locked, yet the rears are still turning. In the real world, it's the other way round, or all wheels are locked. Unless he's got a really ed up brake balancer!
I thought most non ABS cars were setup to lock a front wheel first....
Less likely to spin the car in the event of heavy braking with lateral g's......
But no. The figures have never been revised. I recall a TV program that showed a 993 Turbo make an utter mockery of them.
More interestingly, a 106GTi was within a couple of feet of the Porka.....
Virtually every car puts about 70% of the braking effort into the front wheels, plus brake balancing adjusts it even more to the front (in case its mid corner). Means the rear will very rarely lock up unless your trying real hard & avoiding at the same time which cocks up the weight transfer.
So fronts always lock first.
Unless you've got ABS but then most people don't know what to with that either, hence the latest brake assist systems that do it for you.
Range Rovers Do not stop that quickly, I've got a data logger here if you want to compare. Accurate to within cm's too.
Maybe we could gather some PH car data one weekend...
So fronts always lock first.
Unless you've got ABS but then most people don't know what to with that either, hence the latest brake assist systems that do it for you.
Range Rovers Do not stop that quickly, I've got a data logger here if you want to compare. Accurate to within cm's too.
Maybe we could gather some PH car data one weekend...
Own Morris 1000 and Jag X- type!
Morris 1000 feels fast at 30,could kill at 20 as it is a bit on the
side, and stops, more or less, in accordance with HC. Jag just stops! 
!
The other members of Familie Wildkatze also have old crocks, including the Ford Anglia. It definitely does not like 70!
Morris 1000 feels fast at 30,could kill at 20 as it is a bit on the
side, and stops, more or less, in accordance with HC. Jag just stops! ! The other members of Familie Wildkatze also have old crocks, including the Ford Anglia. It definitely does not like 70!
bluepolarbear said:
The highway code is based on 0.7g braking force, most modern cars will generate around 0.9g stopping from 60mph in around 120feet.
I think the highway code is based on 0.6g or 60% efficiency which is the minimum pass level for the MOT. Thats why a Porsche with
ed brakes can still pass the MOT. I think a lot of high performance cars with anti dive suspension and modern tyres can pull more than 1.2g in the dry. My old Ford Corsair had 90% efficiency in 1964 on cross ply tyres. I also believe the thinking distance in the HC is based on half a second reaction time. It is easy enough to check these numbers but I am fairly sure the HC data is done by calculation rather than measuring an actual car.cptsideways said:
Range Rovers Do not stop that quickly, I've got a data logger here if you want to compare. Accurate to within cm's too.
I know they do not stop as quickly, but they are not that much worse, only about 15 feet more from 60mph, not 80 feet or so. This may be reduced in the real world by a more attentive driver reducing the reaction time, i.e. an attentive driver in a R/Rover will be stopped in less distance than a numpty in a Ford Escort who has not yet seen the danger.....
Muncher said:
Although not eveything stops as quickly as an M3, those distances are way, way out it's silly.
I think the UK Government would gain a bit more respect if they went out and did some real world measuring of a real world average 21 century car.
Ten drivers each get ten goes in something ordinary like a Ford Mondeo.
Highway Code has a whole section on disclaimers anyway. Putting real world numbers in would help their case.
Gazboy said:
Measured with a ford anglia in 1963, (the same car is why we have a 70 limit- it was the fastest it could travel that joe bloke could afford)
i thought the 70mph was due to the shelby cobra being
taken up the newly opened m1 at 160mph or there abouts.
government the said limit was 70 which was the top speed of joe averages anglebox at the time
How about taking it one step further and classifying cars based on their performance and safety or NCAP tests to allow different speed limits, ie New Porsche/Beemer = cat A allowed to do 85 on the motorway, ancient rusty escort = cat B allowed to do 70. This could also then be combined with advanced driving tests?
At the risk of shattering a schoolboy myth, I thought the reason we had 70 mile limits was down to an AC Cobra
doing 130+ at the opening of the M1 and scaring a few people?? I could obviously be hugely misinformed?!? (nice story tho) 
Nice one timf
>> Edited by longjon on Thursday 19th February 10:52
Gazboy said:
Measured with a ford anglia in 1963, (the same car is why we have a 70 limit- it was the fastest it could travel that joe bloke could afford)
At the risk of shattering a schoolboy myth, I thought the reason we had 70 mile limits was down to an AC Cobra
doing 130+ at the opening of the M1 and scaring a few people?? I could obviously be hugely misinformed?!? (nice story tho) Nice one timf
>> Edited by longjon on Thursday 19th February 10:52
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