Red light cameras

rev_henry

flyingscotno1 wrote: »

No, they do not use pressure pads, certainly not modern ones as they are a nightmare for maintenance. They use induction loops, which carry a electrical charge. One is placed before the stop line, one set after the stop line.

I believe they are operational at all times, what happens is when a vehicle passes over the metal in the vehicle disturbs the magnetic field or induction and it registers and input. If the first induction loop notes an input (vehicle) and notes that a red light is lit, it is readied and then as it hits the second loop two evidential photographs are taken, one usually showing the vehicle crossing the white line (actual offence in law, the other proceeding through the junction). It can work out speed (think that is how speed on green works), time after red too. It knows that a red light is lit as it needs the two inputs, one from the red light and one from the loops, hence does not work on amber (and it doesn't need to) but can work on red and amber. Work is being done on cameras that work on radar alone, but I know little about them.

I'm surprised to hear of 1s grace times, I'd have thought most authorites were clamping down on the 'just gone red' offenders and 3s of amber time was adequate enough. I am led to believe it is possible to have a 'trigger speed' set, in which if a vehicle is passing slowly over them it is ignored. I believe this is for the American market however where you can stop, then turn left at red but are going a slow speed so the camera ignores you.

Ah didn't know that.

foofi22

flyingscotno1 wrote: »

No, they do not use pressure pads, certainly not modern ones as they are a nightmare for maintenance. They use induction loops, which carry a electrical charge. One is placed before the stop line, one set after the stop line.

I believe they are operational at all times, what happens is when a vehicle passes over the metal in the vehicle disturbs the magnetic field or induction and it registers and input. If the first induction loop notes an input (vehicle) and notes that a red light is lit, it is readied and then as it hits the second loop two evidential photographs are taken, one usually showing the vehicle crossing the white line (actual offence in law, the other proceeding through the junction). It can work out speed (think that is how speed on green works), time after red too. It knows that a red light is lit as it needs the two inputs, one from the red light and one from the loops, hence does not work on amber (and it doesn't need to) but can work on red and amber. Work is being done on cameras that work on radar alone, but I know little about them.

I'm surprised to hear of 1s grace times, I'd have thought most authorites were clamping down on the 'just gone red' offenders and 3s of amber time was adequate enough. I am led to believe it is possible to have a 'trigger speed' set, in which if a vehicle is passing slowly over them it is ignored. I believe this is for the American market however where you can stop, then turn left at red but are going a slow speed so the camera ignores you.

Going a slow speed does not stop the being caught. I know someone who went <5mph turning left through a red and got caught for it. This happened when they stopped after the lights (behind traffic) and the lights turned red. They proceeded through and were obviously photographed.

I doubt the induction loops can accurately measure speed. They probably offer a 'best guess' (ie the car is going fast or approximate speed) which will then trigger the two photographs. Reference points on the time-stamped photos will be used to calculate the speed of a vehicle.

Dr.Shoe_2

I got a NIP for red light so I told the authority that I'd had to send my licence away to another constabulary and I will forward it as soon as it came back. Never heard anything else. This works on speeding cameras too!

foofi22

Officer_Dibble wrote: »

The speed does appear on the photo calculated by the gatso, tho not type approved for speed enforcement.

Yes exactly, it can calculate an estimate (and display it) but it can't be used as evidence as it is after all just a estimate. The evidence is based on the distance travelled in the photos.

score

can gatso cameras work when they are on the other side of the road, when you are approaching them? Or is it that they have to be on your side of the road?

LeeSouthEast

Officer_Dibble wrote: »

Where did you get this bollox from?

The manager of the safety camera partnership for my area.

Why two tickets and what happened to the NIP's?

One for speeding, one for jumping the red. The NIPs were left out for the sake of simplicity.

flyingscotno1

Officer_Dibble wrote: »

Well he's talking crap.

Traffic light cameras are not type approved for speed offences.

The Home Office have type approved the cameras for monitoring speeds.

http://www.dorsetsafetycameras.org.uk/index.php?option=com_content&task=view&id=296&Itemid=71

LeeSouthEast

Only passing on information from a reliable source. Don't shoot the messenger. I have also not been disrespectful to you, so can the insults.

Lum

I think the confusion comes because there are more cameras than people are aware of. Most people know of Gatsos, the rear facing ones, that come in Speed and Red variants, and most people know of TruVelos, the front facing ones.

The newer ones are made by a company called RedSpeed, and as their name implies they are capable of doing both speed and redlight offences. They also use digital photography rather than film. The ResSpeed housings look pretty much the same as Gatsos so it's easy to not notice them being rolled out.

score

Hi

I wanted to know as it is confusing from these forums where the sensors in the floor are at the traffic lights

Is it the stop white line, or is it just beond this line?

Also what happerns for example if the back wheel hits the sensoras you go past when the light turns red?

Finally are the cameras activated when it turns red or is there a delay for like a second or two?