hi heres one question i,ve always thought about, if its a single carrigeway and speed limit is
50 mph , obvisly we trucks can only do 40 mph but if we were doing 50 mph i honestly can,t see how we would be caught speeding on a fixed camera as it would be set for 50mph, or are they that clever they can do cars and trucks
I learned the answer to this 10 years ago on the outskirts of Lincoln,Swinderby infact on the to British Sugar at Wissington.
The camera never flashed me until one night it had me…and few others and ever since then camera’s seemed to know.
So yes,but I would appreciate it if you would do a proper study…say 4 or 5 times just to confirm it 
I don’t know about all of them but some certainly can. Others on here could tell you the technology used as to whether it uses weight or height.
thanx lads, im amazed they can, i don,t take chances i always slow down,
the other day a foriegn truck passed me i was doing 58mph he went passed me as though i was
doing 40 mph, there trucks should be governed.
From what I remember when this has been posted before, there are load sensors in the road at the critical point of a cameras viewpoint. This is not on all scameras but there are definitely some.
There are several dozen threads on here about speed cameras and where people have been caught by (IIRC) Weigh In Motion sensors on various roads.
Just put ‘Speed Camera’ in the search box at the top right of this page.
gothika:
thanx lads, im amazed they can, i don,t take chances i always slow down,
the other day a foriegn truck passed me i was doing 58mph he went passed me as though i was
doing 40 mph, there trucks should be governed.
They are, but just like some UK drivers some foreign drivers err, …adjust it.
Normally they will have an induction loop buried in the road where the white markings are, you can normally see the diamond pattern of darker tarmac where it is buried, similar to that at traffic lights.
I stand corrected
If you were driving a 7.5 tonner, then you could legally do 50 on a single carriageway and 60 on a dual carriageway ! Your limiter would come into play at 56 ish of course unless going downhill.
Does anybody know how many (and possibly where) the scameras are which can sense the vehicle weights?
What if you are driving a Class 2 vehicle that’s empty and its actual weight is, say 7.25 tonnes? My logic suggests that the scamera wouldn’t flash unless over 55 mph. (50 mph + 10% built in error leeway)
Or would it?
LandyLad:
What if you are driving a Class 2 vehicle that’s empty and its actual weight is, say 7.25 tonnes? My logic suggests that the scamera wouldn’t flash unless over 55 mph. (50 mph + 10% built in error leeway)Or would it?
They don’t weigh the vehicle, just ascertain that the footprint is greater than that of a car. The photos are then checked manually. Therefore the operator would know that the vehicle is subject to the 40mph limit.
Some cameras still use radar (GATSO), not able to detect weights, but can differentiate the size of the radar echo and if its big such as a HGV it can be set to trigger at a lower speed than cars, they’re usually square windows on the box and short white stripes for several metres on the road, usually get you from the back.
Many use induction loops (TRUVELO), usually round windows (beginning to sound like playschool), and usually have 3 white lines across the road just after the loops (3 black tar lines), these loops can also be a piezo sensors, which can determine axle weight, these take a nice piccy of the front of your vehicle using infra red flash so you’ll never know till the NIP drops through the letterbox.
Not all camera boxes have cameras in them all the time, however some scamera partnerships do, some just have a flash unit (GATSO), some have never had cameras in. If you look carefully on both types you can see the lense of the camera if it’s present.
MADBAZ:
using infra red flash so you’ll never know till the NIP drops through the letterbox.
It’s a normal flash but with a magenta filter and I’m led to believe that’s it still noticeable if it goes off 
mrpj:
MADBAZ:
using infra red flash so you’ll never know till the NIP drops through the letterbox.It’s a normal flash but with a magenta filter and I’m led to believe that’s it still noticeable if it goes off
Your quite right, the type approval is for a magenta filtered flash not IR.
A local coach operator regularly gets tickets at 50 mph (legal for a coach) on a 50 mph single carriageway road. So I assume the camera thinks it’s a truck. So much for the manual checks!
The road, BTW, is the A619 Worksop - Chesterfield near Van Dyke nursery.
I’ve often wondered how it all works - but I don’t want to find out from personal experience if that’s OK, thanks. Pete
Would that be a very very local bus/coach operator 
gothika:
thanx lads, im amazed they can, i don,t take chances i always slow down,
the other day a foriegn truck passed me i was doing 58mph he went passed me as though i was doing 40 mph, there trucks should be governed.
Speed can be deceptive in so many ways these days. If you’re in your car, your 58 could have only been 53 due to errors in the speedo 
If you were in a truck doing 58 then you were going faster than the limiter yourself.
I’ve been doing 55mph in a car with GPS giving the speed and a truck which I know maxes out at 60mph past me and that seemed quite fast.
But I don’t care much about speeding anymore, more about fuel consumption. Usually my own!