Safe Speed Forums

http://news.bbc.co.uk/1/hi/uk/7118707.stm

Drivers ignorant of safety basics

Millions of drivers could be putting their lives at risk because they do not know how to make basic safety checks to their cars, campaigners have warned.

Research by the road safety charity Brake suggests that 68% of drivers do not know the legal minimum level of tread on their car's tyres.

The danger of worn tyres is made worse by wintry conditions, Brake stresses.

It is calling for random police checks - and wants the minimum depth of tread increased from the current 1.6mm.

Roadside rescue company Green Flag has joined Brake in the campaign to increase the depth of tread required by cars and vans to 3mm.

Worn tyres can significantly increase braking distances. The head of education at Brake, Jools Townsend, says: "Many drivers are too reliant on their annual MoT and service."

They are unaware of the deterioration that occurs to their vehicle over the course of a year, she points out.

New tyres contain a wear strip moulded into the grooves of the tyre. When the tyre has worn level with the strip, the tyre has reached the legal limit.

Green Flag spokesperson Abi Clark warns that drivers should pay attention to tyre wear and maintaining the correct pressure.

"If motorists fail to take this advice, they could be putting themselves and others at risk from accidents."

Includes following 'box out':


Now there are a lot of problems here. For a start in the box-out, braking distance of 25.9m from 50mph implies 0.98g. That's a very good performance in the dry where greater tread depth will make matters slightly worse, not better.

Then there's the claim of an extra 6 metres stopping distance between new and 3mm tyres. If their figures were correct that implies an equivalent increase in stopping distance to changing the speed from 50 to 55mph. If they were accurate on 39.5m that would be equivalent to increasing speed to 62mph.

NOT ONCE do they mention that the tread in tyres is there to clear water and is only of significance in the wet.

And last but not least, they are chasing rainbows again because DfT contributory factors only put "Tyres illegal, defective or under inflated" in 999 (0.69%) of injury crashes, and 42 (1.55%) fatal crashes.

_________________
Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

It does apply to wet conditions. I found this.


Agreed. They’re quoting brake performance which is usually applicable for dry conditions.

Stopping from 50mph to 0mph in:
25.9m = 0.983G
31.7m = 0.803G
39.5m = 0.645G

I wonder who the independent experts are

I have an irrational hatred of people who shorten their names like this. Roz, Jo and Kat all agree with me on this. And what the heck is Jezz short for? I always think they must be wanting to hide something.

Signed

Mal

_________________
Malcolm W.
The views expressed in this post are personal opinions and do not represent the views of Safespeed.

Thinking out loud:

They tested 4 different tread depths using 4 different vehicles – could they possibly have committed the sin of testing one tyre per vehicle?

Jez or Jezz = Jeremy

Or at least that is what it means for the chap where I work

_________________
Driving fast is for a particular time and place, I can do it I just only do it occasionally because I am a gentleman.
- James May

They seem to be confusing safety and legality. That's not very scientific.

_________________
Andrew.

They also seem to be clutching at straws somewhat, or at least that is the general impression I get with Brake these days.

The only people to benefit from this latest piece of nonsense, would be the likes of Kwik Fit.

Sounds like yet more business for the tyre companies.

What about all the extra pollution from all the scrap tyre carcases.

If driving in wet conditions increases the braking distance, then perhaps driving in such conditions should be banned !!!!!

I wonder what kind of research they did?

_________________
Useless laws weaken necessary laws.

It's bonkers actually. Do you think 40mph?

_________________
Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

These figures are quite clearly wrong!

My copy of the highway code states that the shortest stopping distance (in the dry, with a well maintained car on good tyres) for a car travelling at 50mph is thirty eight metres.

Surely Brake aren't questioning the integrity of such a fine government publication?

mb

If "drivers are ignorant of safety basics" who have we got to blame?
Brake and the government!
because according to them for the last 5 years, all that matters is the speedo and a red circle with a number in the middle

_________________
Speed limit sign radio interview. TV Snap Unhappy
“It has never been the rule in this country – I hope it never will be - that suspected criminal offences must automatically be the subject of prosecution” He added that there should be a prosecution: “wherever it appears that the offence or the circumstances of its commission is or are of such a character that a prosecution in respect thereof is required in the public interest”
This approach has been endorsed by Attorney General ever since 1951. CPS Code

To answer my own previous question, the testing was done by MIRA.

Could MIRA have fallen for speedo overread?
Following through with that speculation: stopping from a true 45mph to 0mph in 25.9m = 0.796G

Oddly enough:

http://www.3mmtyres.co.uk/checkup.asp





A whois of the 3mmtyres.co.uk site gives the registrant as being National Tyres & Autocare (hint) and the first line descriptor of the registrant's address as Integrated Marketing & Advertising Limited,

... so no vested interests there then, none at all, zip!

Maybe there's a case here that requests that BRAKE cease, with immediate effect, any references to HC braking distances in any of their PR's as they have effectively admitted that the distances quoted are outdated in relation to modern cars, and - as a result - reducing speed limits will have zero effect on accident stats

_________________
Simon

Doesn't look like it if the website video is the right video:



One has to ask 92.9 what? however...

_________________
Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

40mph gives:

25.9m = 0.63g
31.7m = 0.51g
39.5m = 0.41g

I'd hope to get better than the second two even in soaking rain - but I find those believeable.

_________________
Paul Smith
Our scrap speed cameras petition got over 28,000 sigs
The Safe Speed campaign demands a return to intelligent road safety

these sorts of tests are so pointless anyway as the breaking distance varies by tyre make, size, brake pads and brake discs. They probably think saying they used 4 vehicles is comprehensive, but it probably barely scratches the surface of the variety of braking distances on offer

ps - not that it matters what brakes or tyres a driver has, if they're looking at the speedo they aint gonna stop in time anyway

And they won't get near those figures on that new shiny tarmac.....the abs on my bike chopped-in at next to no lever pressure....very strange. The van fared no better, locking front and rear wheels on one side quite easily.