Caught Speeding - Question About Photos

[Al U]

Got caught speeding last week and reviewed the photos today. Speed is 80mph on a variable speed section of the M5, which was at 70mph at the time.

My question is about the lines on the road, in the first picture you can hopefully see the back of my car (estate in lane 4) is past the last horizontal line on the road, and in the second picture it's obviously past it. If I am past the lines how have they calculated my speed? I think the camera is one on the side of a gantry, do these work by radar meaning the lines are actually irrelevant?

Not contesting the fact I was speeding or looking to contest the NIP or anything, it's a fair cop but just curious about the lines on the road really.

Edited by Al U on Tuesday 8th October 23:47

[Terminator X]

Afaik the lines are secondary to the camera. You'll get convicted by the camera as it can never be wrong ...

TX.

[pingu393]

I agree with TX in that the camera is secondary. I think the camera is only used if you don't accept the NIP They will then analyse the footage, and if you are guilty, send you the bill as well as the fine and points.

[skyebear]

You should be offered a course at that speed.

[2020vision]

This type of camera, HADEC3X, doesn’t use the lines on the road for its second method of speed measurement, they are from an older type of speed camera that did use the lines.
In the new system, the distance references in the second check. Uses virtual lines that represent distances across the full camera view at the road surface. These are configured within the camera memory.
While your car may be off the marked lines, it is not past the virtual system in the surface grid configured in the device.
An operator must check your forward motion between 2 images spaced 0.350s apart. The distance moved in that time is divided by the time to calculate your average speed. Only if that calculated speed is within 10% of the speed calculated by 2 radars, will the logic allow the record to be processed.
Once that is done the speed shown in the record is validated and used to prosecute.
Some positions where these systems are used will have no lines on the road…well, except for the lanes of course.

[2020vision]

pingu393 said:

I agree with TX in that the camera is secondary. I think the camera is only used if you don't accept the NIP They will then analyse the footage, and if you are guilty, send you the bill as well as the fine and points.

No. The images are always used.

[2020vision]

Terminator X said:

Afaik the lines are secondary to the camera. You'll get convicted by the camera as it can never be wrong ...

TX.

The lines have nothing to do with the camera.

[2020vision]

skyebear said:

You should be offered a course at that speed.

If Avon & Somerset police decide to of course.

[DaveCWK]

2020vision said:

The lines have nothing to do with the camera.

So why are they there?

[ARHarh]

DaveCWK said:

2020vision said:

The lines have nothing to do with the camera.

So why are they there?

Because they don't need to remove them.

[Drawweight]

I got done years ago on my motorbike.

I asked for the photos, on the off chance I could have challenged it.

The photo came back with the crosshairs on the sleeve of my pillion.

‘See if you’d lost a bit of weight they would have missed us’ didn’t go down too well

[Al U]

Thanks for the replies.

I don't use this stretch of road often at all but I do use the M25 regularly and have seen people go through the side mounted cameras doing well in excess of an indicated 80mph and not get flashed. The ones on the M5 must be more sensitive.

I'll be a bit more weary of them now that's for sure.

Waiting to see if I will get offered a speed awareness course, this was on the outbound journey of a weekend away, wondering if I got caught on the way back as well. Time will tell.

[2020vision]

DaveCWK said:

2020vision said:

The lines have nothing to do with the camera.

So why are they there?

I could explain it a different way, but I will just refer you to what I said earlier:
“…they are from an older type of speed camera that did use the lines.”

[myvision]

Al U said:

Thanks for the replies.

I don't use this stretch of road often at all but I do use the M25 regularly and have seen people go through the side mounted cameras doing well in excess of an indicated 80mph and not get flashed. The ones on the M5 must be more sensitive.

I'll be a bit more weary of them now that's for sure.

Waiting to see if I will get offered a speed awareness course, this was on the outbound journey of a weekend away, wondering if I got caught on the way back as well. Time will tell.

I got done on the M25 by a gantry camera at 80MPH round near the M1 i've seen loads fly through there a lot faster and not get done. 05:50 in the morning nothing on the road but me.

[pingu393]

2020vision said:

This type of camera, HADEC3X, doesn’t use the lines on the road for its second method of speed measurement, they are from an older type of speed camera that did use the lines.
In the new system, the distance references in the second check. Uses virtual lines that represent distances across the full camera view at the road surface. These are configured within the camera memory.
While your car may be off the marked lines, it is not past the virtual system in the surface grid configured in the device.
An operator must check your forward motion between 2 images spaced 0.350s apart. The distance moved in that time is divided by the time to calculate your average speed. Only if that calculated speed is within 10% of the speed calculated by 2 radars, will the logic allow the record to be processed.
Once that is done the speed shown in the record is validated and used to prosecute.
Some positions where these systems are used will have no lines on the road…well, except for the lanes of course.

Good stuff. Mine was, as I said, just guesswork.

[E-bmw]

myvision said:

I got done on the M25 by a gantry camera at 80MPH round near the M1 i've seen loads fly through there a lot faster and not get done. 05:50 in the morning nothing on the road but me.

Curious to gear how you know they haven't been done for it?

[myvision]

E-bmw said:

Curious to gear how you know they haven't been done for it?

Never seen it flash before

[E-bmw]

myvision said:

E-bmw said:

Curious to gear how you know they haven't been done for it?

Never seen it flash before

It appears you may be a bit stuck in the past on that assumption as many don't actually flash in the visible spectrum of light these days lots use IR light for the flash so as not to distract.

[2020vision]

E-bmw said:

It appears you may be a bit stuck in the past on that assumption as many don't actually flash in the visible spectrum of light these days lots use IR light for the flash so as not to distract.

The cameras on the motorway use a white flash. No IR on the motorway systems.

[2020vision]

DaveCWK said:

2020vision said:

The lines have nothing to do with the camera.

So why are they there?

I could explain it a different way, but I will just refer you to what I said earlier:
“…they are from an older type of speed camera that did use the lines.”