New Police Tactics M4

[Not on Hercs]

For all you chaps who might nudge the 70 MPH on the way to bases in WILTS/OXON but can spot the marked police cars in time, watch out.

The unmarked cars camouflage themselves by parking on the hard shoulder with hazard lights on and just look like an ordinary break down while using their rearward looking radar/laser to catch speeders.

Keep your eyes peeled!

[16 blades]

Er......just slightly illegal.

You can't stop on the hard shoulder except in an emergency. This applies to the Police as much as anyone else, unless they are attending to render assistance, or have just pulled over an offender.

...but that's not going to stop them doing it now, is it?

16B

[Razor61]

The unmarked cars camouflage themselves by parking on the hard shoulder with hazard lights on and just look like an ordinary break down while using their rearward looking radar/laser to catch speeders.

So they will get hit up the ar$e by a sleepy trucker like the rest of the people sitting idle on the hard shoulder then.

They must of ran out of those 'sidings' ...."For Police Vehicles Only" which tend to be most noticeable on the M5....

On the A361 near Tiverton, the police vehicle hides behind the hedge and the officer pokes his little rays out the hedge...then radios to another traffic vehicle waiting a mile up the road...!

Razor

[Thud_and_Blunder]

...Or you could always leave a few minutes earlier, plan your journey, keep within the speed limit and then everyone would be happy, eh?

:rolleyes:

[Pilgrim101]

Thud

What about the Kuwaiti solution to the speed cameras on the 30, 40 and 50 Highways and the sixth ring road ? ie 5 or 6 AK 47 rounds through the sensor lens.

BY the way, I'm there now and I've got a bottle or two of the Famous Grouse !!:ok:

[Background Noise]

Just as illegal as their camera vans parking on the pavement.

[Training Risky]

Well, Thud, YOU and the rest of the sheep can obey an arbitrary speed limit designed yonks ago for cr@p cars without ABS - if you want to.

The rest of us who can think independently will try to find a way around the problem.

:rolleyes:

[The Nr Fairy]

TR:

IMO, the speed limits are designed less for the super duper fast cars than the slow, dimwitted drivers - that's the bit which hasn't changed in years and is unable to adapt to the environment in which it finds itself.

Jetblast soon, anyone ?

[chippy63]

Well, if you get done, ask to see the evidence and point out the fact that the evidence was obtained by parking illegally?


yeah, right...

[BEagle]

Just phone Plod and report an unattended vehicle on the hard shoulder which appears to contain 2 occupants behaving in a suspicious manner.....;)

Like Pinky and Perky in their unmarked Vauxhall many years ago who were cruising along the totally clear single carriageway section of the A40 between Eynsham and Oxford at 57 mph tucked into the left positively inviting people to overtake them. I spotted them (and the odd light panel in their rear window) and stayed back - but the bloke who couldn't be bothered and floored it as he overtook us both was immediately given the blues and pulled over. If that wasn't obvious entrapment, then what else was it?

[snafu]

After getting busted a couple of years ago, (for doing 37 on a section of 30mph dual carriageway! :mad: ), I decided to see what was available on the Internet. There is a vast amount of information available including directories of all the speed traps in the UK, copies of the Association of Chief Police Officers' guidelines for the use of all different types of equpiment and details of what type of eqipment is used, how it works and the limitations of them all. I'm pretty sure that most people aren't aware of the rules and regs that Plod is supposed to work under and just accept the facts as they are presented to them. Obviously, the best way to avoid being done is not to exceed the speed limit, but I was interested to see the following snippets...

1. ACPO guidelines specify that any equipment should only be used to corroborate an existing suspicion that a vehicle is exceeding the speed limit for the road/vehicle type - ie shouldn't be used to 'zap' every car that goes past until they find one that is speeding.

2. Most types of equipment need to be calibrated in the location that they are to be used at the start and end of a session and the detail recorded by the police officer - they need to drive a calibrated vehicle past the equipment and record the event in their note-book.

3. Some of the equipment is only supposed to be used as long as there is only one vehicle on the road to prevent them receiving returns from multiple vehicles.

Personally, I'd reccommend checking out some of these sites, because it's worth knowing both your rights and the guidelines for the police if you find yourself in this situation.

Alternatively, stay within the speed limit!! :ok:

[lineslime]

Thanks for the heads up. Must go and tell the significant other as she is up and down the M4 daily and will appreciate this.

[RubiC Cube]

Of more concern on the M4 are the safety camera vans (white) which park on bridges and get everybody. They work this tactic all the way from Swansea to Hungerford to my knowledge.

[Wycombe]

....and off the end of the M4 towards Carmarthen (clear straight dual carriageway), there is one of those vans parked somewhere along that section nearly every day.

....and on the A34 just South of Oxford, on a bridge, nearly every day.

Spend the money on catching real villains, for pitys sake (I say that as a resident of a growing town that recently lost it's manned Police Station :mad: )

[lasernigel]

Report in the Telgraph yesterday showing that revenue has increased over four fold since 1997.Clear profit going into treasury coffers last year was £20 million...easy money..stealth tax?Figure it out yourselves.:mad:

[crossbow]

Hey, Ive got an idea. Rather than you guys devising ways of breaking the law. How about you stick to the speed limit and then you save youreselfs money and probably a few points as well but most importantly you save lives.


SPEED KILLS.

[Jambo Jet]

Travel the M4 regularly.

Does anyone actually do less than 70 mph between Chippers and Swindon?

I often sit at 70 on the inside lane and never need to overtake.
Noone cares about speed limits except when the Feds are there.

[Maple 01]

Yes Crossbow, all those poor kiddies trying to cross the M4 at 2 a.m.........:rolleyes:

[Send Clowns]

Speed Kills. Therefore we should have none. Hard to get anywhere though.

However answer this: why 70 mph? Why not 80? Or 50? Why should I stick to this arbitary figure? Even worse, and arbitary figure that was made up on the spot when a typical car, such as a Ford Anglia, could manage 78 mph flat out, and typical handling and braking at the time were dreadful compared even to my cheap, 8-year-old car which has all-round disc brakes, good suspension and excellent tyres.

Crossbow, your post shows such bland, blind, ignorant conformity that I am no longer surprised you show such devotion to Nanny Toneeeeee.

Look into the issue. There are studies showing that the safest group of drivers on some dual carriageways are driving at 85 mph in good conditions. Therefore the "safety cameras" are fining the safest drivers. Others show that the reduction in road deaths, running a constant 5% per annum until the mid 1990s has gradually disappeared in line with the introduction and growth of automatic cameras and lies about speed's role in fatal accidents that politicians push out instead of doing something useful (it's so much easier) and you swallow wholesale and propogate.

[TurbineTooHot]

Crossbow & Maple

How's about a joining of both your very valid points.

Speed kills, very very much so. But I do feel this applies to all areas other than motorways.

These days, most folk I know happily sit on the M roads at 80-90. Sure there are times when a limit lower than 70 is imposed: road works, bad weather etc, and these are imposed for strong safety reasons.

My arguement is for higher limits on the motorways (85), maintainence of the dual carriageway 70, and all other limits, which have been imposed for a damned good reason, to be left in place and enforced.

We all know that the £60 fine is not the end of the financial pentalty (insurance worms stealing more cash). If we subsequently break the law we should pay for it.

The cash however should go directly to worthwhile projects. The problem with the "stealth tax" is that it we do not see any positive results from the fines collected. Where do they go? If the forces who collect them benefit directly, this encourages unscrupulous collection to swell the coffers.

I cannot see an adequate solution to the above problems, apart from raising the motorway limit, and us drivers sticking to the other limits... no giving the miserable buggers an excuse.

Turbine

[crossbow]

Maybe youre right but it would be difficult to justify that to my Ex girlfriend whose sister was killed by a speeding motorist.

[Send Clowns]

Is she an expert on road traffic accidents?

[Gus T Breeze]

Crossbow,

I'm sure my response is of absolutely no consolation whatsoever to your ex-girlfriend. However, it was not the fact that a driver was speeding that her sister was killed, it was his/her inappropriate use of speed in relation to the environment or conditions in which it happened.

[Roland Pulfrew]

Crossbow

Correction. Speed DOES NOT kill.

If speed killed then how did "Dead Dog" manage to drive a 'car' at Mach 1?
How did all those Concorde passengers survive their brush with death at Mach 2+?
The speed kills statement is factually incorrect. Speed does not in itself kill, inappropriate use of speed might, but not speed. As I travel the M1 on a fairly regular basis I get overtaken by lots of vehicles speeding faster than I, but there aren't masses of dead at each junction. In fact the last accident I witnessed on the M1 was caused by slow speed not high speed. And our motorways are still the safest in the country. Please do not trot out the speed kills argument, those with half a brain see though it and it loses its impact.

[crossbow]

OK, maybe the phrase wasn't factually correct. Maybe I should have said " going to fast kills". But at the end of the day, the actual words dont make a difference.... or do they...


What would these people think? (http://news.bbc.co.uk/1/hi/scotland/4224915.stm)

However, Home office research has also shown that a 1mph reduction in the average speed of vehicles on a given length of road will equal a 5% reduction in collisions.

But to really understand that speed kills perhaps you should read
this (http://www.ibinflashed.com/)

[airborne_artist]

It's not speed that kills, it's the kinetic energy, which increases with the square of the speed, so a vehicle travelling at 85 mph has about 1.5 times the ke of one at 70.

Given that you've no ATC/TCAS, and that 50% of the population is below average intelligence, you have to be increasing your chances of being involved in a major accident if you go faster.

[inditrees]

airborne,

at last someone has the grace to bring this thread back into the realms of aviation, i was begining to wonder if i had mistakenly wandered onto the 'Top Gear' website.

[November4]

initial inquiries "support the theory that speed was a significant factor

True it does look like speed was a factor however...the driver being 17 and inexperienced also on a dark road probably didn't help either.

What was the speed limit on the road?
What speed was he doing?
Was that speed approproate to the road conditions at the time?

But.... could the press and police be jumping to conclusions and er speculating over the cause before the full facts are known?


Over 10 years ago in my town, a lady and one of her children were killed when she collieded with a lorry on a bypass. Everyone called for a lowering of the speed limits because the road was so dangerous after this accident.

At the inquest, it was found that she had turned round to look at one of the children in the back and crossed the centre line and hit the lorry.

[Send Clowns]

you have to be increasing your chances of being involved in a major accident if you go faster.Not true at all. It depends entirely on the circumstances.

Crossbow

What those people would think is no more relevant than what any other would think, and clearly one of them though speeding OK. They had no special eduction in road safety. They would know no more about crash investigation than any other member of the public. You are falling into the modern media trap of assuming that involvement in a type of incident gives immediate expertise: that the parents of someone killed by a child molester knows about how to prevent the offense, or the family of those killed in a train crash know all about rail safety. How do you justify the suggestion?

I agree that inappropriate speed, a dangerous speed, was probably a factor as stated. However I never advacated a dangerous speed, and you have not bothered to explain why you think the speed limit is safe, let alone why you think driving above it is always unsafe. I was nearly killed by a lorry driver who was driving too fast. He was doing 35 mph on a village street. That was just 5 mph below the speed limit for that road. It was not an illegal speed. But unsafe speed? Yes.

The lazy assumption that the speed limit is correct suggests that you are the dangerous driver here, not those that drive at 80 on a motorway. Blind adherence to speed limits in poor conditions has caused some of the most dangerous driving I have seen. That is why "speed kills" is such a stupid statement to use.

The article you link to discusses speed on urban streets. No-one here advocates speeding there, so it is completely irrelevant to the discussion (which had you not bothered to read, the posts here or the article?)

[Roland Pulfrew]

Crossbow

So link 1 - inappropriate use of speed kills 4!! Note the Volvo driver was uninjured - so perhaps better training for learner drivers may be appropriate.

Nice 2nd link - proves nothing. If I could find the report, and I can't be bothered cos I am just grabbing lunch before flying again, I think it was the London Ambulance Service who had stated that speed bumps may be killing more accident victims (get to hospital too late, because the ambulance had to slow down for "traffic calming measures") than may be being saved by of the traffic calming measures.

Just as with anything in life there has to be a balance. Reduced speed limits in areas of housing or schools - fair play. But the speed limit on most motorways is now inappropriately slow. The speed limit on motorways is ignored by the majority and it is actually idiots with the attitude "Well I am doing the speed limit so I am staying in the outside lane" who cause many of the accidents on major roads. Caused because instead of moving to the left lane they cause bunching, which causes tailgating, which causes excessive use of brakes which leads to accidents. So again inappropriate use of speed. There should actually be a minimum speed limit on major routes (except when weather precludes otherwise). That way if you aren't prepared to travel at the speed of the route get off it.

Thank God tomorrow is Friday so I can look forward to another 3 hours on our motorway network.

And the sun is shining above cloud, and the sky is blue, and relax. Mission bubble on. :cool: :cool:

[WebPilot]

Oh dear, the speed argument.

"Speed" does not kill - inappropriate or bad driving does. This may involve speeding as an element. The following table showing accident causes is taken from the DETRs own report into road safety.

Inattention: 25.8%
Failure to judge other person's path or speed: 22.6%
Looked but did not see: 19.7%
Behaviour: careless/thoughtless/reckless: 18.4%
Failed to look: 16.3%
Lack of judgement of own path: 13.7%
Excessive speed: 12.5%

Furthermore, a large number of the excessive speed accidents are not caused by /illegal/ speeds. Avon & Somerset Police published some stats that showed just 30% of excessive speed accidents took place in excess of the speed limit, and 2% of excessive speed accidents involved a stolen vehicle. The 68% of remaining excessive speed accidents involved speeds inappropriate for the conditions.


"For every one mph reduction in speed accidents reduce by 5%."

This is utter hogwash, coming from a pair of TRL reports that used some very creative statistical methods and relying on some very big assumptions. A causal relationship was assumed, and no allowance was made for any knock on effects. In fact, if you look at the stats, you find that the safest roads in the UK are the fastest - the motorways. This is nothing more than god old fashioned "spin".

[airborne_artist]

send clowns

You've omitted to consider the possibility of mechanical failure on your own vehicle, eg tyre blowout - in which case your speed will have a direct bearing on the time taken to come to a halt (and the number of lamp-posts, bridges etc. you have to avoid).

In the days of hub caps (and hidden wheel nuts, therefore) a friend took his newly serviced totty-trapper up to 100 on a quiet M-way. Slowed to 90, imagine his surprise when his O/S front wheel carried on at 100. He lived to be extracted from a mashed pile of scrap.

[crossbow]

Excessive speed: 12.5% so it does kill then... or do the 12.5% not count

[Roland Pulfrew]

No it doesn't. READ the report. On 12.5% of occasions excessive speed contributed to an accident. The report DOES NOT mention whether people were killed or not. So you cannot assume that in 12.5% of the accidents someone was killed!

[Send Clowns]

Ah, Crossbow - in time-honoured fashion for your side of the debate, you read all you need into a misinterpretation of one statistic! Great, who need bother think that can assume, eh?

Try a statistic of 4%, if you read Web's whole article, although since that is by definition inappropriate speed in excess of the limit, even that is not really an argument in your favour. All crashes caused by excess speed suggest that the driver did not judge his or her speed well. Since your idea of speed judgement places far too much emphasis on the limit, you actually wish to reduce people's judgement!

airborne

All such mishaps are also both much less likely and much more survivable (either by not crashing or surviving the crash)with modern cars than Ford Anglias, yet the limit is the same. The argument stands: all risk can be eliminated by banning driving. Assuming we must drive, we balance risk and progress on our journey. The balance has shifted towards higher speeds, the law has not followed!

[WebPilot]

Crossbow, taking one single point from an argument and ignoring the others is the usual tactic from those who cannot argue the point in substantive terms.

"Speed kills" lacks any useful meaning and is dangerously misleading as I have demonstrated above.

[hyd3failure]

But that doesnt get away from the fact that going too fast kills you.... the end. Next thread

[glum]

And if I may be so bold, perhaps one about military aviation...?

[WebPilot]

"But that doesnt get away from the fact that going too fast kills you.... the end. "

Actually, no. Stopping too fast is what kills you.

[10forcash]

The 'speed kills' mantra is basically trotted out because it's the only objective measurement that can be made. if there was a measurement for how good / bad a car, driver, road, junction, pedestrian, cyclist, horse rider, tyre, brakes, suspension, road surface etc. etc. without being subjective, then that would be used instead. Speed is an easy target because its measurable and has been demonised (sp?)by the sensationalist press.
Like smoking, there is no clear correlation between speed and death, there are approximately 27% of the population that have cancer resistant genes, hence the '70 year old on 40 woodies a day' and the '400bhp and no accidents in 30 years'. i'm not saying that good driving skills are genetic, although quick reactions and hand / eye coordiantion may be....
BTW, one reason given why women are cr@p at reversing is that they have no d1ck - lack of hand - eye coordination..work it out
Cheers,
10forcash

[Pontius Navigator]

Funny where the cameras are. I did a long distance drive from God country to the south west and my RWR did not cheep once and there was only a handful of Truvelo cameras. Round High Wycombe tho there were cams every 100 yards, it seemed like.

In 600 miles the warner never cheeped once, except for Woolies and garages, but the GPS listed almost all of them. <g>.

[10forcash]

Pontius,
I take it that you're a (fellow) yorkshireman then?
Cheers,
10forcash

[J Urby]

2 Years ago I was lying in a hospital bed in the John Radcliffe hospital in Oxford after having my leg put back together after a rather failed attempt at a parachute jump. In the bed opposite me was a bloke who had been cut out of a car after attempting to overtake a lorry and hitting another car head on. He was wondering if he clould get compensation for his accident. when I questioned him about what had happened, he claimed he was a very safe driver and never speeded; infact, when he overtook, he left the car in top-gear and crept past the lorry!! he was Fu**ing lucky to say the least As has been said, speed kills but it is inappropriate speed - he was going too slow. If you overtake then ignore the speed limit and get it over as quickly as is safely possible for the road conditions or wait. Unfortunately, speed cameras do not take these manuveres into consideration and are apparently leading to more road deaths as people try to overtake but remain within the speed limit. And crossbow, before you answer, i am not content to sit behind a lorry doing 50mph on a road i know to be perfectly safe at higher speed. :E

[BEagle]

"Even worse, and arbitary figure that was made up on the spot when a typical car, such as a Ford Anglia, could manage 78 mph flat out"

Never managed to get more than 70 indicated out of my old 100E Anglia. Everything shook and shuddered, the sidevalves took a hammering and oil smoke came up through the floor...

Cars when that woman Castle was Minister of Transport were, in general, dreadful. For example, that Anglia:

Had seats which tipped forward
Was full of sharp edges
Had drum brakes all round
Had a 3 speed gearbox with no synchromesh on 1st.
Wasn't required to have seatbelts
Had wipers which used manifold air pressure in a pneumatic reservoir.
Had an optional extra - a heater/demister!
Had a dealer-installed extra - a manual screenwash system
Had no rear screen heater
Had no wing mirrors, just a tiny interior mirror
Had skinny cross-ply tyres
Had the roadholding qualities of a supermarket trolley


Yet I was legally allowed to drive this deathtrap on roads at speeds which the nanny state so beloved of some of the tits on this thread now think of as highly dangerous for ultra safe modern cars?

The only difference between an ill disciplined child playing in the road hit by a car at 40 or hit by a car at 60 is the size of the smear left on the road.

Don't want your kids killed? Keep them OFF the roads. As we were all once taught...

[Lafyar Cokov]

I do remember seeing a statistic that stated that 98% of all accidents were caused by speed - I can only assume that 2% of accidents occured between 2 parked cars!!!

It's a bloody dangerous world out there!!

[16 blades]

Whilst speed CAN kill, it does not mean that speed WILL kill. You can drive like a ****wit at any speed. And driving like a ****wit will ALWAYS kill.

If a car is doing 40 down a 30 road, and somebody pulls out in front of it because they havent looked, thereby precipitating an unavoidable collision, speed will be listed as "a factor", even though it has cock-all to do with the accident happening in the first place. This is happening because accident investigators have been ordered by this govt to record accidents in this way to justify their thievery. You can argue that the collision would be less severe if the first car was going slower, but the fact remains that the collision wouldn't have happened in the first place if the second driver hadn't been a ****wit and looked where he was going. If the collision never occurs, the speed of the first vehicle is completely irrelevant.

16B

[John Eacott]

Gee, you guys are lucky. Try our Nanny State of Victoria, population 5 million, which budgets $A400 million a year in State income from speeding fines :eek:

3kph tolerance on speeds registered by cameras/radar.
40kph zones through school areas, some 24 hours per day :confused:
As well as RBT (random breath test stations), we now have Roadside Drug testing. Under a 12 month trial ATM.

Getting back to the thread opener, if the rozzer is facing away from the cars being pinged, it would be quite difficult to prove in court that your vehicle was unarguably the vehicle shown on the radar/laser. No?

[Beeayeate]

In all this it seems to me that one point has not been aired enough - the driver is ultimately responsible for his/her actions. If the driving attitude is bad or worse, lacksidasical, any reslultant incident is the driver's fault, even some prat pulling out in front from a side road! Your driving attitude should not let such a thing turn into a metal bender. Essentially, when driving think ahead . . constantly.

While I'm here I'd just like to mention the well-known "Speed Kills" advert. This shows a car braking hard ("smoke" coming from the front wheels) but still knocking over a child in a "main street" and at 5 or so mph over the limit. Vivid and graphic stuff.

My question is, why are the car's rear wheels not shown as under braking as well? They continue rolling at all times throughout the sequence. In this case I would say that it wasn't speed that "killed" the child, it was bad car maintenance.

Or maybe I'm being too cynical . . . .

[16 blades]

Rear wheels dont tend to lock under heavy braking, as front brakes tend to be considerably more powerful than rears.

If this car had been travelling at 30 mph, it would have stopped........here!

What that advert should have said was:

"If the driver hadn't locked the front wheels by incorrect technique and panic-braking, it would have stopped a f**ksight sooner and remained under control, permitting the driver to steer around the child in the road"

Or maybe:

"If this child's parent(s) had exercised a degree of control over him and stopped him from legging it into the road........etc"

16B

[woody0381]

One thing evident to me in the said commercial, is that the (slightly aged) vehicle did not appear to be equipped with ABS, as would be the case with many modern vehicles - which would have stopped the car in a far shorter distance.


Woody

[Send Clowns]

ABS wouldn't have stopped the car any more quickly, but it would have retained the control to steer around the kid. Kid was primarily at fault in that accident, but uninsured!

[ShyTorque]

<<One thing evident to me in the said commercial, is that the (slightly aged) vehicle did not appear to be equipped with ABS, as would be the case with many modern vehicles - which would have stopped the car in a far shorter distance.>>

Woody, sorry but you are wrong! ABS does NOT stop vehicles in a "far shorter distance", it is designed to prevent wheels locking up by sensing relative wheel motion - a slowing / locked wheel triggers the electronic brain to pulse brake pressure, so that the wheel continues to turn, preserving directional control of the car. In some circumstances it can EXTEND the stopping distance (try it on snow, for example - or perhaps, don't). Fitting ABS doesn't change the laws of physics.

It does seem that the rear wheels of the car in that advert were not braked sufficiently - best stopping distance occurs when all 4 wheels are on the point of locking up. Many vehicles have a brake pressure limiter to the rear wheels, so that the rear wheels don't lock first and overtake the front ones on a corner - not that anyone should be using heavy braking in a corner. It does look like that advert has been made to emphasise a point - perhaps that vehicle should have been put through a brake check, rather than merely blaming speed...?

[woody0381]

Sorry, my post was inaccurate. I meant to imply that ABS would have stopped the car in a shorter distance in comparison to having both of the front wheels locked for the duration of braking as in the commercial.

I accept that stopping distances will vary greatly depending on road conditions, type of vehicle, etc.

[Duckbutt]

My question is, why are the car's rear wheels not shown as under braking as well? They continue rolling at all times throughout the sequence. In this case I would say that it wasn't speed that "killed" the child, it was bad car maintenance.

This is only circumstantial I accept, but I read somewhere (possibly Autocar mag) that the car used in the film had the the rear brakes disconnected for a more dramatic visual effect.

With regard to stopping distances, I am open to correction but is it not correct that having antli lock brakes does not necessarily shorten the stopping distance but by keeping the front wheels turning, retains the driver's ability to change direction in a controlled manner?

[crossbow]

More police tactics are displayed here (http://news.bbc.co.uk/1/hi/england/cornwall/4233127.stm) . Please everyone be careful of this one.

[StopStart]

Damn......that'll put paid to my car stealing antics :rolleyes:

[BEagle]

Excellent- hopefully such rat traps will catch the avaricious, workshy, scrounging little gits who steal from cars.

But why not wire the cars to supply 400 volts between steering wheel and driver's seat on demand. Better still, make that 40 000 volts!

No doubt the bleeding heart pinko wet liberal sandalistas on this thread will view such scum as 'underprivileged victims of capitalist society' or some such tosh. Bolleaux - they're THIEVES. One of the few things which Saudi Arabia has going for it is the penalty handed out (or rather off) to thieves.

[crossbow]

wow.... Blimey Beags....

So, you don't like Thieves then?

[c-bert]

Having had my car broken into 3 times (the last 2 they took nothing because there was nothing to take!) I fully agree with BEagle. The more violent the punishment the better.

[BEagle]

Nor do I like illicit dole scroungers, illegal immigrants, phoney assylum seekers or any other spongers who prey on decent society...

But thieves and drug peddlers come top of my list for extermination.

[Beeayeate]

blades . . .
Rear wheels dont tend to lock under heavy braking, as front brakes tend to be considerably more powerful than rears.

Think you've got that wrong blades, with the weight transfer dymamics the rear wheels will be lighter loaded so will tend to lock all the more easily, they definitely wouldn't keep turning as shown in the advert. Doubt you're right in your "more powerful front brakes" assertion either. The situation shown in the advert is just plain fairy tale and about as believable as Blair saying "We have no plans to raise taxes".

However, I entirely agree with the second part of your post. :ok:

Another thought, could it be that the driver of the car in the advert was too worried about Gatsos with his attention on his speedo rather than the watching the road?

It's all academic anyway, as a driver, no matter what you do you will be wrong!

[Pureteenlard]

Actually it's a neat little device called a brake proportioning or brake bias valve that stops your rear brakes locking before the fronts. Race cars don't have one. They have an adjustable bias that can be se to the drivers preference . . .
So the rear wheels do keep turning after the fronts have locked unless you have a faulty valve. If they didn't your car would have a serious propensity for swapping ends everytime you braked hard.

[16 blades]

Beeayate,

Accept your point about effective centre of mass transfer, however, remove the wheels from your car and compare your rear discs/calipers with your fronts. Front brakes are ALWAYS considerably more powerful than rears, because thats where most of the cars weight is. Also, due entirely to ECOM transfer under deceleraton, front tyres have several times the grip available to the rears, hence can be braked harder.

Because most cars have braking systems like this, few of them need pressure limiters in the rear brake lines. Some have them due to the nature of their brake / suspension systems (Citroen for example).

16B

[Trumpet_trousers]

....why doesn't someone invent a sideways-looking radar for cars, so that if it stays in the middle lane of a Motorway for more than 2-300 yards with nothing in the inside lane, the car immediately self destructs? Maybe then we'd see a dramatic rise in lane discipline? :ok:

[Tallbloke]

16 blades:

Correct...notice how the fastest motorcycles have twin 310mm discs on the front wheel and a single 230 mm disc on the back

AND NOW, LADIES AND GENTLEMAN!

ABS does stop cars in a shorter distance.

Firstly, the most obvious, the punter just pushes as hard as possible and a computer manages the rest, ergo human error is removed.

And now the science, as explained at length to me by a Professor of Vehicle Dynamics during one of many lectures about Mechanical Vibrations:

ABS systems work by momentarily reducing the pressure applied to the brake pads after a wheel has locked. After some set period the pressure must be reapplied to allow braking to continue. What modern ABS systems do is to modulate the braking effort so as to set up resonance in the suspension system. A system in resonance has much larger oscillations than one which is vibrating not at the resonant frequency of the system. Larger oscillations mean that the wheel bounces up and down much more than normal; hence the reaction with the road surface is greater. Friction is a function of reaction (F=mu*R) hence retardation is enhanced. Thus if the suspension system can be forced to oscillate at it's resonant frequency retardation is increased. Vehicle dynamics engineers have used this principle to enhance the benefits of ABS.

Never mind all that, THE greatest benefit of ABS to most drivers is that they can manage to retain directional control of their vehicle even when they have entered a situation far beyond their abilities. Hence drivers can still steer their vehicle at maximum braking effort, something even F1 drivers struggle at.

[Beeayeate]

Correct...notice how the fastest motorcycles have twin 310mm discs on the front wheel and a single 230 mm disc on the back

Yes, on motorcyles. Much shorter wheelbase (and track) making weight transference typically more immediate. So accentuated front braking is wise as pretty much all the bike's weight will be on the front wheel (singular). Not so with cars though I believe, the dynamics are different.

Liked your bit about ABS though, very explicit. We know that if your ABS cuts in you stand a better chance of stopping without skidding - but yer front suspension gets knac£ered. :hmm:

Mmm . . I remember Maxarets on our aircraft, anti-lock units (do they still use them?). Does your explanation mean that the oleos werealso bouncing up and down during all those landings on rain-soaked runways?

Just kidding. Thread has drifted way off course. But I still think that anti-speed advert is a con.

[16 blades]

The dynamics of braking on a motorcycle are identical to those of a car (in a straight line at least) - I say this as a biker.

I think the bike analogy was used because a bike's brakes are readily visible, whereas a cars are not.

16B

[FJJP]

Maximum braking is achieved milliseconds before the wheels lock up. This is when the maximum friction between tyre and road surface is experienced. If the wheel locks, the friction raises the temperature of the tyre compounds which then melt, forming a liquid film between the tyre and the road. This film acts as a lubricant and increases the stopping distance.

Aircraft have been fitted with ABS for decades [called 'maxarets']; the principles are identical, as are the effects.

[brakedwell]

My 1954 MG TF has two slave cylinders to actuate the front brakes shoes and only one in the back. In the unlikely event of wheel locking up under heavy braking it is always the front pair.

[Beeayeate]

OK, looks like I'm outvoted here - so vehicles have more powerful brake units at the front than the back. Looking at my own motor they look the same though, disc and caliper size.

Doesn't detract from my position though. I still think that advert was/is mis-representative and misleading in terms of the car's screen performance.

[BEagle]

Surely you remember when cars only had disc brakes on the front - and drums at the rear?

[Razor61]

why doesn't someone invent a sideways-looking radar for cars, so that if it stays in the middle lane of a Motorway for more than 2-300 yards with nothing in the inside lane, the car immediately self destructs? Maybe then we'd see a dramatic rise in lane discipline?

Trumpet

You should run for Transport secretary.........:ok:

[Mick Stability]

This small mod will help with the addition of two internally stowed wing mounting mini-HARMs.
http://www.geocities.com/tdrarh/COLLECT/XF007/GRAPHICS/CARS/BMWZ8/Bmwz09b.jpg

[BossEyed]

Beeayeate: Another thought, could it be that the driver of the car in the advert was too worried about Gatsos with his attention on his speedo rather than the watching the road?

Unlikely; the location is a high street. When was the last time anyone saw a GATSO there? Or in front of a school? Nope, stick 'em somewhere they can catch lots of people - not the high hazard but lower exposure areas where the revenue may be less...
:rolleyes:

[16 blades]

...or just research the law and provide an effective defence, since the police rarely follow procedure correctly when nicking people for speeding.

..and when you are aquitted, make sure you apply for costs against the police and CPS, just to twist the knife.

Gave me great satisfaction, that did.

16B