How do speed cameras work?

[TyneSoft]

Hi all.

 

Pretty obvious question but when I ask how they work, do the roads in question need to have certain markings on them so the camera can figure out the speed of the car, or can there be no markings at all?

 

If the latter, how would the cameras calculate how fast you're going?

 

Thanks.

[Foot]

I think it depends on the type of camera. Fixed ones tend to have lines on the carriageway but camera vans obviously operate without the need for lines.

[Baron99]

Hi all.

 

Pretty obvious question but when I ask how they work, do the roads in question need to have certain markings on them so the camera can figure out the speed of the car, or can there be no markings at all?

 

If the latter, how would the cameras calculate how fast you're going?

 

Thanks.

 

Believe that the more modern ones use radar / laser ranging to instantly determine your vehicle's distance & speed. Alternatively all you need are 2 cameras set a known distance apart & if you travel between the two, above a certain number of pre-calculated seconds or mins, then you're spending.

[Cyclone]

The older ones still use radar to trigger, but the road markings are used for evidence, there are 2 photos taken a know time apart.

[tlangdon12]

As per cyclone's response, the lines are only there to double-check the evidence from the speed camera. The cameras are self-contained and work without the line on the road.

[willman]

Truvelo = small(as in thin) lines on both sides of carriageway with one camera, can get you coming and going depending how obtuse the camera is angled.Usually infra red flash.

Same camera does both lanes.

Gatso camera with rows of (usually) wider painted lines on one carriageway only - get you from behind,previously with a flash but i don't think they all do these days.

Speed over distance - they aren't triggered by how fast you pass the camera,they record the average speed between two cameras.

Most motorway gantry cameras have no line markings as such(but they work off fixed lane markings),the camera is triggered electronically.

 

Road markings are often for prosecution evidence only.

 

Most Gatso use radar tech to do the speed checks,Truvelo use sensors in the roads to detect your speed.(Truvelo tend to be the forward/backward ones).

[ANGELFIRE1]

They work by collecting a tax. Of course it cannot be called a tax because the general public would not like it at all. So they find a name that will fool the masses, road safety camera sounds almost saintly don't you think.

 

I believe radar and infra red are the gubbins of how they work.

 

Angel1.

[tinfoilhat]

They work by collecting a tax. Of course it cannot be called a tax because the general public would not like it at all. So they find a name that will fool the masses, road safety camera sounds almost saintly don't you think.

 

I believe radar and infra red are the gubbins of how they work.

 

Angel1.

 

Have you tried not speeding? I do 20k a year and I've never been "taxed".

[Baron99]

They work by collecting a tax. Of course it cannot be called a tax because the general public would not like it at all. So they find a name that will fool the masses, road safety camera sounds almost saintly don't you think.

 

I believe radar and infra red are the gubbins of how they work.

 

Angel1.

 

You might want to call it a tax but it's a self-imposed one if you have to pay it. I've never been subject to it & I suppose their are millions of drivers out there exactly the same.

[jaffa1]

Believe that the more modern ones use radar / laser ranging to instantly determine your vehicle's distance & speed. Alternatively all you need are 2 cameras set a known distance apart & if you travel between the two, above a certain number of pre-calculated seconds or mins, then you're spending.

 

This is correct, they can calculate the average speed you have been doing between the two cameras.