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How slow do you need to go
Posted: Thu Feb 18, 2010 10:28 am
by David
I go through the Muirhead speed camera every day and instinctively check my speedo. Today was no exception but, at an indicated 30, I got a double flash

. The lorry alongside and it might have been going a mile or two faster (but still within the 30 limit I would have thought) - what are the chances of a ticket. Do these cameras ever get it wrong? How do they tell which lane has triggered the flash?
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 10:31 am
by philthy
most probably someone travelling in the other direction, Ive had that a few times.
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 10:52 am
by ironside
Probably someone coming the other way . . .
The two flashes are two photos taken half a second apart. They check the camera hasn't got it wrong (and which lane triggered it) by checking the distance you have covered between the two pictures on the white paint lines on the road in front of the camera.
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 11:09 am
by meatball
The guys are correct! I wouldn't worry. You could test you speedo with a gps? They are fairly accurate.
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 2:24 pm
by robin
ironside wrote:Probably someone coming the other way . . .
Agreed!
ironside wrote: They check the camera hasn't got it wrong (and which lane triggered it) by checking the distance you have covered between the two pictures on the white paint lines on the road in front of the camera.
Agreed this is what they should do, but I wonder if they do - i.e. perhaps they send out tickets to all involved and wait for you to contest it, then they do the sums and cancel the ticket if there is not enough evidence of speeding to take it further. Not only would this generate the most revenue, it would also be the most efficient use of (hu)manpower.
It is your moral duty (in Scotland) to set off any camera on the other side of the road whenever it is safe to do so
Cheers,
Robin
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 2:31 pm
by Andy G
ironside wrote:Probably someone coming the other way . . .
The two flashes are two photos taken half a second apart. They check the camera hasn't got it wrong (and which lane triggered it) by checking the distance you have covered between the two pictures on the white paint lines on the road in front of the camera.
Yup - i used to time my approach on the A68 cameras to do exactly that - takes a bit of skill

Re: How slow do you need to go
Posted: Thu Feb 18, 2010 2:38 pm
by Corranga
robin wrote:It is your moral duty (in Scotland) to set off any camera on the other side of the road whenever it is safe to do so

I'm intrigued. How?
Imagine all the people that could be getting a speed camera pic with a Lotus in it
chris
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 2:53 pm
by alicrozier
They are set up for folks travelling away from the camera. When you trigger the sensor while going towards it you are already out of shot (certainly for the 2nd pic).
Not ideal in convoy scenario though (thanks Andy).

Re: How slow do you need to go
Posted: Thu Feb 18, 2010 3:00 pm
by Rich H
Doppler RADAR - they only 'see' speed not direction

Re: How slow do you need to go
Posted: Thu Feb 18, 2010 3:29 pm
by tut
Having been behind the hooligan Gordon on the A68, I saw first hand his method of setting the camera off for cars coming in the opposite direction.
However I was pretty sure that it was a single flash and not a double. Maybe someone could check it out, although I noticed recently that I could not get them to play.
tut
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 3:39 pm
by scott_e
do mobile cameras vans use flashes ?
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 3:46 pm
by tut
Certainly not visible ones, think they are I/R. They work over a much greater distance than Gatsos which are old technology. Can get you from 0.5 miles away, when you see one you are too late.
tut
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 3:58 pm
by scott_e
cheers Tut ... im expecting a letter in the post soon i guess. Think i got pinged on the 31st. 3 weeks is about right for the paper work aint it ?
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 4:01 pm
by tut
Nope, it has to be posted to you within 14 days. Scam Vans normally come through within four days as they are all digitised and computerised.
tut
Re: How slow do you need to go
Posted: Thu Feb 18, 2010 4:03 pm
by scott_e
your like a fountain of knowledge

that's cool thanks, I can breath easy then. Cheers for the good news.