Speeding Nip

[scubatony]

I have just received a NIP (Notice of Intended Prosecution) for doing 84mph on the M4 between J35 & J34

 

Now here is what actually happened;

 

On Friday 4th July which was a bright sunny day

I was traveling east along the M4 and as anybody who knows the area, at that particular stretch it starts to climb uphill,

so to keep a steady 70ish (not 80ishor 90ish) I put my foot down to compensate for the hill.

 

As I crested the hill my speed increased and I eased off the accelerator and took my sunglasses off.

 

It was then that I noticed on the A4222 Cowbridge Road parked on a bridge going over the M4 a camera van,

it’s the only bridge on that' stretch of motorway.

 

Now, heres the thing,

I knew that I had been doing 70ish climbing the hill so it goes without saying, on the cresting the hill,

it wouldhave been late 70’s if it had climbed up to 84mph it can have only been for amatter of seconds.

 

My understanding is the “Two Tenths Rule”, so using acalculator found here;

 

http://www.calculatoredge.com/civil%20engg%20calculator/Speed%20Distance%20Time.htm

 

1,760 yards to the mile

 

Divided by 10 = 176

 

Times by 2 = 352

 

352 yards (which is two tenths) at 84mph is 8 seconds

 

Before you say “Fair Cop”, there is something that you should know,

there were people passing me in the outside lane and it could have been the signal from their car that caught the speed activation.

[Aretnap]

What's the two tenths rule? Google has never heard of it.

 

A laser speed gun takes around a third of a second to take a measurement, so if your speed only crept as high as 84 for a few seconds, that would still be ample time to get a reading.

 

The photos (or actually stills from the video) would show if there was any possibility of the reading coming from another car. The police aren't obliged to let you them at this stage, but often will if you write back with a polite request. Note that you still have to name yourself as driver within 28 days of receiving the NIP or risk being charged with the more serious offence of failure to provide driver details - entering into further correspondence doesn't stop the clock.

[scubatony]

Aretnap

 

Looks like it migfht be my mistake, on the 2 10th's rule, see below

 

http://www.lawfirms.com/resources/traffic-tickets/speed-violations/how-speed-is-measured.htm

 

This is for "Pacing" see first paragraph

 

What about the rest of the problem cresting the hill etc. ?

[SabreSheep]

How does cresting the hill impact on the speed measurement taken by the speed gun?

[scubatony]

If you drive up the hill (a long hill say ) you increase your revs to compensate for the reducing speed.

 

Once you crest the hill you ease off the revs saving fuel and thereby slowing down.

 

For example

=========================

So going up the hill 3,000 rpm 70mph

Cresting the hill 70mph

Going down the hill 2,000 rpm 70mph

========================

Its only an example

 

In answer to your question there is very small time lapse between cresting the hill and getting back to the the limit.

 

Thats why the van was parked where he / she was because they knew about the hill, also facing a westerly direction.

 

It would not work if they were facing the other way

[citizenkain]

your speedometer still works when your going up a hill though! if your speed was increasing you would take your foot off the accelerator and touch the brake,thats how you slow down in a car.........

[richard_se11]

The links you refer to seem to be foreign (American?), are there any English sources.

[SabreSheep]

Playing devils advocate here

 

So your excuse for being over the limit is you were accelerating to maintain speed on the hill and as a result of reaching the top of the hill meant your speed increased above the limit while the revs came down?

 

Did you not see the incline coming to an end?

 

Did you not apply breaking to remain inside the speed limit?

 

Sorry Sir but it is your responceability to control your speed at all times. Blaming a hill aint gonna cut it

[BazzaS]

2 main issues :

1) do you think there is no way you were going 84?.

If so, ask to go to court & insist they produce evidence.

 

2) " Other people were going faster" is irrelevant to your case, unless you can show they aren't being prosecuted (and even that would be an uphill struggle, basing it on "rule of law" / need for the law not to be applied in an arbitrary manner).

 

In the end : if you were speeding - accept the points / fine (or SAC if offered). If not : ask to take it to court where you can ask them to prove your guilt / confirm they were using a HO approved device / show the device remained appropriately calibrated.

[ericsbrother]

OK you think tyour speed was less than that indicated by the measuring equipment. You are right, it is all down to the azimuth and cosine effects on the laser or radar gun so the error can be up to 10%. then there is vectoring- how your vehicle is travelling relatively to a fixed direction such as the road lane. if you are crossing lanes or going round a bend that will have the effect of making it seem you are going faster than you really were to the observation equipment set up on a bridge that is measuring straight down the road (cannot do anything other than measure a straight line).

The bad news is that the rules for calibration of these devices do not take this into account and so a magistrate, unless they are methematicians or physiists will not accept your arguments because the Home Office say the guns are approved devices and thus infallible when calibrated.

There are other more minor errors with this type of devices such as the shape of your vehicle where the beam is measuring will produce an amount of scattering and also the doppler effect but again no-one will want to listen.

Your best hopeon arguing about the calibration is really about the way it was set up that day and what lane you were in and the position of the device above if in a different lane. I would bet that the device was calibrated on a flat road with the device on a tripod at the side of the road so no azimuth and a smaller cosine error to calculate.

If you get the cahnce of being offered a speed awareness course them plead guilty and accept it, if no course you wont get any more points for having your day in court, just a bigger fine is more likely.

[BazzaS]

OK you think tyour speed was less than that indicated by the measuring equipment. You are right, it is all down to the azimuth and cosine effects on the laser or radar gun so the error can be up to 10%. then there is vectoring- how your vehicle is travelling relatively to a fixed direction such as the road lane. if you are crossing lanes or going round a bend that will have the effect of making it seem you are going faster than you really were to the observation equipment set up on a bridge that is measuring straight down the road (cannot do anything other than measure a straight line).

The bad news is that the rules for calibration of these devices do not take this into account and so a magistrate, unless they are methematicians or physiists will not accept your arguments because the Home Office say the guns are approved devices and thus infallible when calibrated.

There are other more minor errors with this type of devices such as the shape of your vehicle where the beam is measuring will produce an amount of scattering and also the doppler effect but again no-one will want to listen.

Your best hopeon arguing about the calibration is really about the way it was set up that day and what lane you were in and the position of the device above if in a different lane. I would bet that the device was calibrated on a flat road with the device on a tripod at the side of the road so no azimuth and a smaller cosine error to calculate.

If you get the cahnce of being offered a speed awareness course them plead guilty and accept it, if no course you wont get any more points for having your day in court, just a bigger fine is more likely.

 

Are the courts convinced by cosine error?

 

http://metro.co.uk/2008/06/25/genius-who-failed-to-do-the-maths-218415/

 

http://news.bbc.co.uk/1/hi/england/south_yorkshire/8132032.stm

 

Noting the latter was in the High Court as an appellate case, so binding on lower Courts?

[scubatony]

ericsbrother

I have never said my speed was less than indicated ! ! ! !

Part of my thread

“it had climbed up to 84mph it can have only been for a matter of seconds.”

BazzaS

http://metro.co.uk/2008/06/25/genius-who-failed-to-do-the-maths-218415/

 

http://news.bbc.co.uk/1/hi/england/south_yorkshire/8132032.stm

 

Noting the latter was in the High Court as an appellate case, so binding on lower Courts?

These news articles are both about the same party, whose case failed and have nothing whatsoever to do with my thread.

Thanks

[zumbanikki]

ericsbrother

I have never said my speed was less than indicated ! ! ! !

Part of my thread

“it had climbed up to 84mph it can have only been for a matter of seconds.”

BazzaS

http://metro.co.uk/2008/06/25/genius-who-failed-to-do-the-maths-218415/

 

http://news.bbc.co.uk/1/hi/england/south_yorkshire/8132032.stm

 

Noting the latter was in the High Court as an appellate case, so binding on lower Courts?

These news articles are both about the same party, whose case failed and have nothing whatsoever to do with my thread.

Thanks

 

 

don't really get the point of your quotes

but back to you, you admit that you were doing 84 mph that's 14mph over the speed limit so cant say its speedo fault.

[scubatony]

goodbye

[BazzaS]

ericsbrother

I have never said my speed was less than indicated ! ! ! !

Part of my thread

“it had climbed up to 84mph it can have only been for a matter of seconds.”

BazzaS

http://metro.co.uk/2008/06/25/genius-who-failed-to-do-the-maths-218415/

 

http://news.bbc.co.uk/1/hi/england/south_yorkshire/8132032.stm

 

Noting the latter was in the High Court as an appellate case, so binding on lower Courts?

These news articles are both about the same party, whose case failed and have nothing whatsoever to do with my thread.

Thanks

 

I was replying to the poster who mentioned cosine error, on your thread, advice which you might have relied on - so I was explaining why I thought you shouldn't follow that advice.

 

goodbye

 

 

People have made suggestions to try to help but you admit you were speeding. Yet you "shoot down" contributors.

 

What did you expect? A magic wand to wave??

One wonders what your expectations are and if they are realistic.