Safe Speed Forums

Do they activate when someone crosses the white line with their wheels? or is it activated when crossed by the front of the car as the wheels are further back from the very front of the car I ask because I routinely see people stopped at traffic lights with their fronts and sometimes wheels over the white line. Cant this cause an offence?

It is an offence to stop with the front of your car over the stop line, but AIUI red light cameras will only catch you if you actually proceed through the junction when the lights are on red, or at the very least have the rear of your car visible to the camera.

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"Show me someone who says that they have never exceeded a speed limit, and I'll show you a liar, or a menace." (Austin Williams - Director, Transport Research Group)

Any views expressed in this post are personal opinions and may not represent the views of Safe Speed

In most cases they are "activated" when the car passes over embedded road-surface sensors. The old type use doppler radar similar to gatso speed cameras (some are just that, to catch people speeding through the lights)

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56 years after it was decided it was needed, the Bedford Bypass is nearing completion. The last single carriageway length of it.We have the most photogenic mayor though, always being photographed doing nothing

The offence of failing to obey a traffic signal is committed if ANY part of the vehicle CROSSES the stop line while the red light is showing.

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I am not a lawyer and can't give legal advice. I do have experience of the day to day working of courts and use that knowledge to help where possible. I do not represent any official body and post as an individual.

It's quite funny too because junctions cycle ASLs have two stop lines, but the idea is that the first one you reach has a little broken filter lane leading to it, so cyclists don't have to commit the offence of breaking the first solid white line to get past it and into the ASL box.

Many road painters don't bother doing the littel filter bit though, making the bit with the cycle picture painted in it impossible to get to without committing the offence.

So will a camera catch you if you went over marginally? As I see loads of people with their car fronts over the line by a few feet sometimes.

Or will it know that the car has stopped and not register it as the same offence as jumping a red light?

Of course, a competent driver would always stop a few feet short of a white line at an ATC, because:
1 - he has manoeuvring room if an emergency vehicle comes up behind and cannot get through, perhaps because of a traffic island
2 - he also has a limited amount of manoeuvring room if the vehicle behind looks like it's not going to stop without hitting him
3 - he has allowed room for vulnerable cyclists to come to the front and be clearly seen
4 - where there is a left filter lane and he is in the right lane, left filter traffic and pedestrians who may be crossing from the right have more chance of seeing each other (and vice versa), and
5 - he can see all the ATC's without having to contort his neck, if the ATC across the junction fails. How often do you see drivers twisting their neck to see a light that is out of view above the top of their windscreen, just because they stopped too close?

Good Drivers just Drive

So will a camera catch you if you went over marginally? As I see loads of people with their car fronts over the line by a few feet sometimes.

Or will it know that the car has stopped and not register it as the same offence as jumping a red light?

I understand the camera is only fired when you pass over the induction loop at quite a speed, i.e. fast enough not to stop for the junction at all.

Drifiting over the line as you stop not going to fire the camera so I figure you're OK, unless the junction is being monitored by CCTV by the local council as I think they might have the power to issue a ticket for the offence, they certainly do for box junction offences.

Probably not, the camera only activates after a set period after the red light appears (although this might only be one second), and it is the sensors which it monitors, not the line. Sometimes these are, well, not really in the right place. I believe they are piezo strips not inductive loops in both the Gatso and RedSpeed devices. Traffic signals also have inductive loops on for monitoring traffic which are nothing to do with any camera device.

Also most traffic lights don't have any cameras, and there is probably a minimum speed at which you have to travel in order to trigger the camera anyway. That is a guess as I haven't read the instruction manual, but it seems likely there's some minimum speed.

I don't think there are currently any traffic light cameras using radar, although there may be one "one the way". Seems strange to me, as the best way to monitor a line would be to have sensors either side of it. Not that I agree with the use of any automated justice devices.

Edit: Also the sensors aren't always connected to every lane. Most profitable lanes first.

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Andrew.