Wurzel

iTrader: (1)

The one were there is an old astra parked on the side of the road and a car which looks like an old Cavalier is skidding towards a dummy standing in the middle of the road.

Now that you all know which one I am talking about can someone explain to me why the front wheels are locked and smoking and the rear wheels are still turning, do cavaliers not have brakes on the back wheels or what? I would have thought all 4 wheels would be locked if it had no ABS which it obviously didn't otherwise it would not be locked up and smoking at the front.

Also and extra 5mph = 21ft extra stopping distance in the dry! is this really true.???

hail-hail

It's an interesting one this.
The advert is there for shock purposes, much like the current drink driving campaign and the wear seatbelts in the back campaign.

It is pretty obvious that if I was in my scoob with ABS and 4 pots, for example, that I could be doing 50 and stop before that old Cav.

The point that they are trying to make is that if you break the speed limit, you take longer to stop. Which is pretty sound advice.

johnfelstead

Non ABS cars have a valve in the rear brake system that restricts brake line presure if the car goes into a heavy dive. It's a safety feature to stop you spinning the car due to locked rear brakes.

Now if they had a TypeRA and had the DCCD set with some lock %, the fronts wouldnt lock up and the rears would share the braking load due to transfer torque through the centre diff.

Subaru Impreza STi5 Type RA V-Ltd, safer than your average shed.

Reffro

Hail-Hail I'm sorry to say the message didn't get through to you. This reply is not a personal attack by the way just a common sense explanation of the adverts message and the physics involved. There is no way you could outbrake an old cavalier stopping at 30-0mph if you are doing 50mph, and that is guaranteed. And this is exactly the argument the advert is trying to combat, the 'Oh that's just a crappy car my nice shiny new one will brake better than that attitude' which we tell ourselves to allow us to break the speed limit in town.

Your probably sat there wondering how this can be, so I'll work this out for all to see. The supposed braking distance for a car stopping from 30 mph is 45ft, at 50 mph its supposed to be 125ft. Now assuming that your brakes are the very best, you might, and I mean might stop in about 60ft, but 45ft nahh I doubt it very much. But regardless of that fact the killer is the reaction time of the driver. Nobody drives around foot hovering over the brake pedal waiting for a child to run out in the road, so at 30mph the 30ft you cover before applying the brakes seems reasonable, but at 50 mph its stretched to 50ft before braking, therefore to stop your car from 50mph, faster than the crappy cavalier travelling at 30mph (remember the total distance is only 75ft) you need to be able to brake from 50-0mph in 25ft..................

STi wanna Subaru

iTrader: (1)

Why not show an expensive car then like a BMW or a Merc?

Tiggs

that advert for axa, there's no way those pigs could fly that fast in real life....

Wurzel

iTrader: (1)

Tiggs has Timbo33 got rid of his car????

Only My M8 who lives round the corner from him says it was parked on the side of the road for a while and has now gone.

ChrisB

Hoppy did some brake tests didn't he? Could stop from 100mph quicker than a Porsche 911 IIRC.

Made a mockery of stopping distances in the Highway Code.

Reffro

I don't dispute the braking distances in the highway code are complete pap, but the distance covered before reacting to the danger haven't changed, and that's what needs to be emphasised. Ignore which car you drive and its performance whilst braking, it doesn't matter, the faster you drive the longer it takes you to stop. So take more care in town, adhere to the speed limit, and you might avoid having the accident in the first place. Its not a bad message is it really?

marty_t3

Well the car in the Ad is a sunny.... with no ABS and it's front wheels locked up, but, it doesn't matter what car it is. It's not a good example of speed kills.

The driver of that car is obviously not showing enough compotency to perform a routine emergency stop, something you must be able to do before you even get a licence!! If you lock up your wheels and don't pump the brake to unlock them, you fail your test as you do not have the skills required to be allowed on the road.

It's more like an Ad displaying poor driving rather than anit-speeding. If the wheels were not locked up the car wouldn't have hit the dummy.

Is that the sort of incident the government are claiming is an accident caused by excessive speed???

How about this example.

A car drives along the road at 20mph. A kid walks out in front of the car. The driver is too busy trying to change the channel on his radio that he doesn't notice the kid until it's too late... he hits the kid at 5mph.

Now if the driver was only doing 15mph he would have had time to stop before getting to the kid.

That must be speed related accident as well

^Qwerty^

If you watch the very start of the advert you'll see that the car has also left the 30mph zone, or at least thats how I see it.

(if we are picking fault) (not that it matter either)

Chrisgr31

What I want to know with that Ad is how fast is he still going when he hits the kid, and would the kid fly as much in reallife? That should set the more mathematically able thinking!

Chris

DrEvil

<devil's advocate mode>

Anyone remember the Green Cross code stuff as a kid? Don't see ads like that anymore do you! Works both ways, pedestrians need to be made more aware too (and cyclists)...

BOB.T

Correct me if I'm wrong but doesn't the highway code take it's figures from a Zephyr?

I get the message but I still think the ad is a crock of sh*t

SWRTWannabe

Well said DrEvil!

It would be good to see that the amount spent on educating drivers about the dangers of the road is equalled by the amount spent on educating kids about the dangers of the road. But I bet it isn't

hail-hail

Reffro, fair points. I wasn't actually trying to say that I could stop from 50 quicker than that car from 30. I was trying to say that stopping distance does not come down to a set of stats set out in the highway code.
As you rightly point out it's mainly down to the driver, conditions, and I'm sure a whole other number of things.

I honestly think that the advert is trying to shock us into going slower in 30 zones. It would have been a point better made if the car had of been a 'safe' car (merc, BMW, volvo, whatever)

I am certainly not advocating speeding in 30 zones
I just belive the point could have been better made in a better car.

Reffro

I think we ought to be working at the Department of Transport, I know I can do a better job than Darling and his cohorts.

johnfelstead

When i was at Junior school (aged 10/11) we had the green cross code ramed down our throat. We had cycle proficiency tests every year. We also had a schools road safety quiz run by the Police. 4 kids from each school represented the school, a bit like university challenge LOL, and battled it out on questions on road safety based on the highway code. I was one of the 4 kids to represent my school and we won this quiz after loads of rounds of knockouts, then a semi and then a final for schools in the police area.

These quizes were in front of the whole school, so all kids got to hear the questions and answers and got involved actively in road safety.

because we won we got to spend the day with GMP trafic division and got to see what they have to deal with. It was a real eye opener and i am convinced this has had a positive impact on my whole driving "career".

From that eye opener, when i was at college i saw the police ofering pre-driving training at the local skid pan/training centre they used. So i signed up for that and at 16 i spent a few weeks under the supervision of the Police driving instructors, showing me how to drive, how to handle skids, how to do 1:3 hill starts, stuff like that. So before i ever drove on the road i was a pretty well trained driver in the fundemantals and my mental aproach was right.

This did 2 things for me. Firstly it introduced me to handling a car without the need to worry about other traffic so i could really learn. Secondly, it introduced me to the fact that you can learn a huge amount in a short time from an experienced coach. (you reading this Saxo Boy )

I havent heard of this kind of thing being run in schools/colleges for years now, which is crazy when you consider how much you can get out of this type of thing.

Education, education, education my ****.

fast bloke

AFAIK The stopping distances in the highway code are based on an Allegro (probably with crossply tyres.) Same thing with the 70 speed limit on motorways. An Allegro was deemed to be an average car when much of this work was produced and flat out it would do..... 70 MPH.


p.s. - If the guy in the ad had been doing 60 he would have been somewhere else when the kid/dummy stepped out

SWRTWannabe

Wow - I remember doing that myself. Didn't win though, thanks to some kid on our team getting his questions wrong

T.C

Reaction time is defined as:

"The time that passes between the moment the driver see's the need for action and the moment he takes that action" The average driver takes a minimum of 0.7 seconds from the moment he decides to take action to the moment he actually takes that action, this is called the thinking distance, and the speed we travel at in miles per hour we will travel in feet distance. So at 70 miles per hour we will have travelled 70 feet before we even think about applying the brakes.

Most drivers take over a second, so the thinking distance published in the Highway code is the minimum distance assuming the driver, the vehicle and the roads are in 100% A1 condition. Any variation and you can add quite a distance to those figures.

So whilst modern vehicles are quite capable of stopping in phenominaly short distances, it is the driver equation that has to be considered overall, ie the amount of concentration being applied, reaction time, forward observation and planning and anticipation.

On the advanced Police courses many years ago, we were not taught about out and out speed, but to get ourselves in the correct place on the road with the right gear engaged using all our powers of observation, planning and anticipation, coupled with what is called observation links, and speed would come as a natural by product, and it works. But the reaction time still remains a conatant.

However, going back to the advert, why don't the advertisers combine the two safety messages. "Observe the posted limits, and by the way kids, choose somewhere sensible to cross the bloody road"!

LG John

I don't have an 'in' reputation at the moment so I won't get too heavily involved for fear of 'lets all flame saxo'

What I will say is that I could jump out of my car with a rope and stop the car with my bare feet in a shorter distance than the highway code. I know its there to encourage people not to speed and to observe the 2 second rule but who are they trying to kid. Pretty much any car that can get an MOT can pull up in a shorter distance. Just my very humble opinion

Brun

A further 21 feet?
A 1965 Ford Anglia would take an extra 21 feet to stop from 35 mph (compared with 30 mph). The braking effort assumed is 0.7g and matches the rather old fashioned and pessimistic figures in the Highway Code. Most modern cars will brake at 0.9g (in the dry and on the flat) and will be able to stop in an extra 17.6 feet instead of an extra 21 feet.

But speed isn't the only thing that affects stopping distance. Hills and rain also have big effects. Let's look at rain. In the dry stopping from 30 mph takes around 66 feet. But in the rain stopping from 30 mph takes about 83 feet, that's 17 feet more, and just about the same real increase as the "5 mph over" claim. So perhaps the advertisement should imply that "rain kills"?

Another very important factor in real world stopping distances is driver attention. Simply observing the hazard and planning action takes a very significant amount of time. If the driver wasn't paying attention to the road ahead when the hazard appeared then the reaction clock doesn't even start until he looks back ahead. We end up with these four important components

Markus

I can see the point of the advert, but when I see it I always think. hmm, maybe the kid should look where he's going, or use a proper crossing, etc... I know, opening myself up to a nice flame grilling, but as Alex said, Green Cross Code. This advert is yet again painting the car and driver as pure evil and the cause of all accidents, whilst this is true in many cases, there is the point that it is pedestrians who also cause accidents, and then have a go at the driver even though they were in the wrong.

As for the current drink driving ad (where the car rolls into the garden killing the kid). Very powerful indeed. And the seatbelt one is good as well.

jasey

When I was a lad - I was driving through Richmond when two pissed girls stepped into the road just as I was getting to them. I wasn't speeding - they were knocked down - one of them nearly came through the windscreen (ended up behind the car face down in a pool of blood) - the other one was knocked forward about twenty feet.

Had I been speeding I would have felt worse than I did - and I felt pretty bad.

When cars come into contact with people it aint nice - I don't think I would like to see an impact at 50

Jase

Hoppy

I had a go at this ad last time it was given blanket coverage, not becuase I disagree with the message (ie it takes longer to stop the faster you're going) but at the 21ft bit for an extra 5mph. The ad just lost credibility with that exageration so I did a few tests.

Nothing very scientific, just a quiet country road with a marker post and when I passed it, I slammed on the brakes. Marked the spot. Did it again. Same spot. Then I did the same thing from 35mph and marked a new spot. And again. And again.

Each time the extra distance required from 35mph was six feet. I concede the point about thinking distance so lets add another five feet for that. We're still at only 11 feet longer, not 21 feet.

Thinking time is the real killer at greater speed, but that's a more difficult message to get across.

Richard.

boomer

Have a read of the somewhat long article at http://www.safespeed.org.uk/killspeed.html which specifically related to this very biased "advert".

One of the more interesting scenarios is...

Let's compare different cases of a scenario which we believe to accurately represent the real world.

In each case the conditions are as follows:

- It's dry and clear.
- It is a built up area. A 30 mph speed limit applies.
- We have an average driver in an average car.
- A pedestrian suddenly steps into the road (from a previously hidden position on the left) 100 ft ahead of the car.
- We've calculated braking distances based on standard physics equations and an assumption that a car with modern brakes and tyres will slow at about 0.85g. This assumption is reasonable.

Case 1.
The car is being driven at 35 mph with full attention focused ahead. The driver takes about 0.75 seconds to recognize the danger and start braking. During this period the car moves forward 39 feet. The car's brakes are applied with full force and the car stops in 48 feet. 87 feet have been covered by the car and the pedestrian at risk is still 13 feet away.

Case 2.

The car is being driven at 30 mph. The driver is half way through making a speedometer check when the pedestrian steps out. (It is known that speedometer checks take about 0.8 seconds.) During the remaining 0.4 seconds before the driver refocuses ahead the car travels 18 feet. The driver takes about 0.75 seconds to recognize the danger and start braking. During this period the car moves forward 33 feet. The brakes are then applied with full force and the car stops in 36 feet. 87 feet have been covered and the pedestrian is still 13 feet away.

Case 3.

This time we have an inattentive driver and the car is being driven at 30 mph. The driver takes about 2.0 seconds to recognize the danger and start braking. During this period the car moves forward 88 feet. The brakes are then applied with full force and the car slows for just 12 feet before impact with the pedestrian. The speed at impact is over 24 mph.

Case 4.

An advanced or experienced driver approaches the danger area. The driver recognizes the inherent danger of the hidden area (from which the pedestrian in our examples emerges), and reduces speed. (Our driver probably positions further right too, giving more space, but that's a completely separate issue.) From the reduced speed, when the pedestrian does step out our advanced driver is easily able to avoid a collision by gentle braking.


It is well worth taking the time to read the whole article (and also other sections of the web-site).

mb

Reffro

Nobody knows why the rear wheels are still turning.

The 21 ft bit is correct, the stopping distance at 30mph including your reaction time is 75ft, for 35mph its 96.25ft using the calculations from the highway code.

Oh and its a Nissan Sunny saloon that's doing the skidding.

[Edited by Reffro - 2/11/2003 2:42:30 PM]