172mph 'on a rural road'...

[martine]

http://news.bbc.co.uk/1/hi/england/oxfordshire/6312673.stm

[jont]

So we must immediately impose a 40mph blanket speed limit on all rural roads to stop this sort of dangerous driving

There's a couple of places along the A420 I can imaging doing those sorts of speeds - all of which are dual carriageway. Only really "rural" in the same sense that the M54 in Shropshire is rural. (This is not to say that I condone speeding, just am fed up with the typical knee jerk reaction that will be put out by the likes of Brake).

[martine]

So we must immediately impose a 40mph blanket speed limit on all rural roads to stop this sort of dangerous driving

There's a couple of places along the A420 I can imaging doing those sorts of speeds - all of which are dual carriageway. Only really "rural" in the same sense that the M54 in Shropshire is rural. (This is not to say that I condone speeding, just am fed up with the typical knee jerk reaction that will be put out by the likes of Brake).

I sort of agree but I really don't think there's anywhere on British roads where 172mph is sensible. Anyone know what the stopping distance is at that sort of speed (even in a 911)?

Even if it's one-way (as in m-way or DC) if there was any other traffic being overtaken it would frighten the life out of them. Even if it's one-way and the road's empty, the margins for error are very small both for the car and driver. Can you imagine a tyre problem at 172 or a slight tracking problem or a bit of damp road or, or...

At least tracks are one-way, others are there expecting high-speeds, have large runnoff areas and there aren't any lamposts etc to hit.

[James]

I am in agreement that speed in itself is not dangerous, it is when it is inappropriate for the circumstances that it becomes dangerous. I don't know the road in question so do not know about its layout, junctions, slip roads or physical features. In addition none of us can know what it was like at the time in terms of other road users being present, their mindset and layout. Therefore I cannot comment on whether I feel his speed was inappropriate.

What I will say is that there are very few places in my opinion where this sort of speed will be safe or justified. Evan at 140mph with blue lights going could be pretty unerving on alot of roads given the sensitivity of attention required and the respect one must have to the proximity of a possible fatal error. That and faster can be done safely and calmly but I wonder whether someone who has "borrowed" (which I read to mean dishonestly taken without consent) a 911 has the mindset to drive in this way. I would hazard a guess this is a well covered up joyride.

[Gareth]

What is the opinion of the relative safety of 159 mph (or whatever it was) at night, and 172 mph in daylight (assuming that this was the case)?

[James]

It was 159mph. Not sure about your question though Gareth? Do you mean a comparison between the two?

The difference with the 159 case was 1) There was video footage so therefore complete evidence as to the road layout/conditions and other road users and something to work with and 2) There were alot of politics surrounding whether or not this guy could actually claim a "police purpose".

This 172 seems like an employee who could not resist, and temporarily forgetting any opinions on either, I am sure the 159 driver was alot safer than the 172 driver...

[7db]

Weird - "A motorist has been arrested on suspicion of driving at 172mph on a rural road"

I don't recall the offence of "driving at 172mph on a rural road", and speeding's not arrestable, so have they gone straight in for the DD charge?

[vonhosen]

Weird - "A motorist has been arrested on suspicion of driving at 172mph on a rural road"

I don't recall the offence of "driving at 172mph on a rural road", and speeding's not arrestable, so have they gone straight in for the DD charge?

Any offence is arrestable, where the arrest conditions are satisfied.

[James]

The same power of arrest for dropping litter is used for murder.

[7db]

Well there's a great improvement with the new rules...

[James]

Is supposed to make things easier and simpler, and to be fair it does, but only after you have understood them. Anyway, getting back to the 172mph...

[TripleS]

Is supposed to make things easier and simpler, and to be fair it does, but only after you have understood them. Anyway, getting back to the 172mph...

Must we always have things simple and easy - rather than appropriate and just?

Best wishes all,
Dave.

[jont]

Anyone know what the stopping distance is at that sort of speed (even in a 911)?

There's a website here:
http://www.csgnetwork.com/stopdistcalc.html
that lets you play with stopping distances, which also suggests a coefficient of friction value of 0.8 as being about as good as it gets (I expect StressedDave can give more realistic figures).

Using u=0.8 and 170mph gives a distance of 370m.
By comparison, the HW code gives 60mph as 73m, but using the u=0.8 formula gives a distance of 46m.

To get 73m at 60mph, u has to be 0.5, which the website suggests is typical with poor condition tyres. At 170mph, this stopping distance would be 570m

I think these distances are only only stopping distances - ie no allowance for reaction time at the speed you are travelling.

I wouldn't like to speculate which is more accurate, but if someone would lend me a 911 Turbo and Bruntingthorpe airfield, I'd be happy to provide some more accurate numbers....

[crr003]

I sort of agree but I really don't think there's anywhere on British roads where 172mph is sensible. Anyone know what the stopping distance is at that sort of speed (even in a 911)?

About 500M?? HC type calc.

[MGF]

I would guess the police were as much concerned with the taking without consent than the speeding as far as the arrest was concerned.

The 'borrowing' of the car implies the driver is irresponsible and if that irresponsible behaviour is present in his driving then there is a good chance the speed was very dangerous for the circumstances. It is of course all specualtion but I think the probability is high that this driving was more dangerous than PC Milton's (assuming Milton's was dangerous).