31 replies to this topic

[TroyTempest]

Hi,

With regards to the white lines on the road where speed cameras are, what is their purpose? I always presumed they are there to prove the offence. I assume the timer is shown to be highly accurate and that the lines are likewise (or can be measured again after the fact) and that those two presumptions together prove the offence. Rather than the radar just bouncing off whatever the hell you fancy.

Does that mean if the lines are not there, the offence cannot be proven? Say for instance where the road has been resurfaced?

Edited by WhatAmIDoing, 14 June 2012 - 02:36 PM.

[Dave SYP]

Hi,

With regards to the white lines on the road where speed cameras are, what is their purpose? I always presumed they are there to prove the offence. I assume the timer is shown to be highly accurate and that the lines are likewise (or can be measured again after the fact) and that those two presumptions together prove the offence. Rather than the radar just bouncing off whatever the hell you fancy.

Does that mean if the lines are not there, the offence cannot be proven? Say for instance where the road has been resurfaced?

You haven't, have you WAID????

[TroyTempest]

No I haven't but I keep passing two cameras on Embankment thinking what if you did tank it through there?

[Dave SYP]

There WAS a picture in the national press of 2 SYP officers doing just that whilst gesturing to the camera in Sheffield some time ago. I think they were 'dealt with' by PSD.

[TroyTempest]

yeah in a front facing camera, which I thought was a bit odd. How do those deal with motorbikes, but then again, that's another topic. I also, didn't mean in a job car.

[Reado]

each white line is 5mph, i think, two photos are taken the however many lines have passed between the two photos is the ruff speed.

[wanabe]

I was always under the impression that the lines are there to determine what speed you were traveling. If you pass the camera speeding it will flash once as you enter onto the lines and again as you near the end of the line. They then see how many lines you have passed in a certain time frame to work out the speed you were traveling. If it a forward facing camera it's different, can't really have a giant flash when you are driving towards it.

Beat me to it. Not the fastest typing on my phone!!

Edited by wanabe, 14 June 2012 - 02:54 PM.

[SBG]

interesting - My view would be yes you can but the CPS would not run it.

If you are caught by a mobile camera the police officer operating it must form the opinion you are speeding and use the device to verify it.

As fixed camers do not have a police officer there they use the secondary check, but it is only a check, so you have technically committed the offencebut i suspect they would not run it.

I was always under the impression that the lines are there to determine what speed you were traveling. If you pass the camera speeding it will flash once as you enter onto the lines and again as you near the end of the line. They then see how many lines you have passed in a certain time frame to work out the speed you were traveling. If it a forward facing camera it's different, can't really have a giant flash when you are driving towards it.

The camera uses either loops or radar to determine the speed. the lines are a check

[TroyTempest]

This is interesting, http://www.abd.org.u...to_checking.htm, which is sort of what I was expecting.

but obviously not authoritative.

[-AJ]

I was always under the impression that the lines are there to determine what speed you were traveling. If you pass the camera speeding it will flash once as you enter onto the lines and again as you near the end of the line. They then see how many lines you have passed in a certain time frame to work out the speed you were traveling. If it a forward facing camera it's different, can't really have a giant flash when you are driving towards it.

Beat me to it. Not the fastest typing on my phone!!

Forward facing cameras, the Truvelo type have a magenta filter on the flash - they do flash. They have 3 lines on the road infront of the camera, and and 2 induction loops set into the road before them. As you pass over the loop it activates - and measure the speed between the 2 loops - if you're speeding it takes a picture, and the 3 lines indicate how fast you were going.
- Edit - the megenta lines is because as you may be aware red light does not dazzle or ruin your night vision - hence internal lights on ships is red at night time. And is used in photographic dark rooms..

As someone else said the lines on a Gatso indicate 5mph each - the radar says you're speeding and it takes 2 pictures - the number of lines between each picture are counted and you are sent a ticket based on that.

Average speed cameras use numberplate recognition between two points

there is also a third type, which has the 2 induction loops in the ground and a grey post which has a socket in it, where a speed camera van can plug itself in. This is a part time speed trap - and is used for mobile speed monitoring from a distance. I don't know how they work legally now cause usually the plugged in van is around the corner from the loops..hence it's location..

Edited by -AJ, 14 June 2012 - 03:28 PM.

[TroyTempest]

So how do front facing cameras capture motorcyclists? I guess they don't which is why they're not all front facing.

[SkinSte]

So how do front facing cameras capture motorcyclists? I guess they don't which is why they're not all front facing.

Like you say, they don't.

[eddie_wakey]

So how do front facing cameras capture motorcyclists? I guess they don't which is why they're not all front facing.

I saw some average cameras on the a1.
Most were forward facing but every now and again there were a rear set...

[TroyTempest]

*makes mental note of front facing cameras and others missing white lines....."

[-AJ]

I saw some average cameras on the a1.
Most were forward facing but every now and again there were a rear set...

Aye. Like the safety camera vans - they usually have front AND rear facing cameras in use...

Edited by -AJ, 14 June 2012 - 03:53 PM.

[David]

hence internal lights on ships is red at night time. And is used in photographic dark rooms..

Point of order, that's wrong, but that's not for this thread.

[RunningTings]

Speed cameras still exist/work? That's a serious question, thought they were a thing of the past due to that recent review. Ones around me don't work and haven't done for years. But to answer the point, each line is 5mph as someone stated and are there as a secondary measurement. The camera decides the speed itself (hence why it flashes), and the lines are used simply for more concrete evidence.

[Dean2011]

White lines indicate 10mph or so that was said on a cop program. (could also be 5mph as said above)

As for average speed camera's well.... We all know the obvious flaw within that area.

[MerseyLLB]

White lines indicate 10mph or so that was said on a cop program. (could also be 5mph as said above)

As for average speed camera's well.... We all know the obvious flaw within that area.

Unfortunately I have been led to believe that the 'flaw' has been rectified.

[TroyTempest]

Speed cameras still exist/work? That's a serious question, thought they were a thing of the past due to that recent review. Ones around me don't work and haven't done for years. But to answer the point, each line is 5mph as someone stated and are there as a secondary measurement. The camera decides the speed itself (hence why it flashes), and the lines are used simply for more concrete evidence.

Not convinced, some cameras cover multiple lanes so you'd need a decent way of accurately determining who was travelling faster if two cars are captured. With the angles the camera are at you might very well need sophisticated interpretation to compare one against the other.

Also, what happens when the radar bounces off something other than the car? I've set off Gatsos on the opposite carraigeway before now.

[The Constable]

I was always under the impression that the lines are there to determine what speed you were traveling. If you pass the camera speeding it will flash once as you enter onto the lines and again as you near the end of the line. They then see how many lines you have passed in a certain time frame to work out the speed you were traveling. If it a forward facing camera it's different, can't really have a giant flash when you are driving towards it.

Beat me to it. Not the fastest typing on my phone!!

Its basically this:

These lines are like markers to cover the distance

Because speed is calculated:

S = D/T

Where S is speed , D is distance and T is time.

Divide Distance by time and that gives you speed roughly

[TroyTempest]

Thankyou for the elementary maths lesson

[David]

That's not fair WAID. I see it as part of a helpful and comprehensive answer. You might know what he means, but there are others who might not

[BigCopSmallTown]

Point of order, that's wrong, but that's not for this thread.

Whats wrong? Ships do have red lights internally at night in accomodation areas for crew - usually the Navigation Officers deck.

As for the forward facing cameras not getting motorcyclists - there have been several publicised convictions of motorcyclists exceeding the speed limit as confirmed by a forward facing camera. If you blast through it and record an exceedingly high speed then efforts will be made to trace the vehicle and a prosecution pursued.

[i-plod]

I remember seeing a case in the paper where a motorcylist was caught doing something like 45 in a 30. The camera had lines on the floor but had clearly only gone on the radar reading as when queried it was proved he had been travelling at the legal limit and it was said that the radar must of been interfered with by a bus that was going the other way. So not sure if procedures have changed since the story a few years ago but they obviously hadnt checked the distances between the lines in that case.