Safe Speed Forums

Does a red light camera distinguish between those who just go straight through a red light at speed and a person who is waiting at a red light but accidentally sets off through the red light from stationary (thinking that the lights had turned to green when they hadn't).

The reason I ask is that I did it just the other day at a stupid crossroads where you can't see the lights clearly when at the front of the queue at the stop line. The position of the lights are level with the stop line so you they are above you out of sight. Virtually all other junctions have duplicate sets of lights spaced about 8 feet behind each other so everyone has clear sight of the traffic signals. Not at this junction though !

Will I get an NIP for this? I believe the camera is one where there are senses in the road which trigger the camera off. I didn't see a flash though and would have only crossed the line at 5-10mph.

If it flashed, then you will probably get done - the speed doesn't matter. People are being prosecuted for moving over the line in order to let emergency vehicles through, so you don't have much of an argument there. The camera only takes a snapshot, and doesn't see the full picture of what you did or why - automated prosecution means no consideration of circumstances.

It should be obvious really, but why didn't you stop where you could see the lights? The lines are a guide as to where to stop, but there is no reason at all why you shouldn't stop before them...

Didn't see a flash.

I was not in familiar territory, it was 11pm at night, in the corner of my eye a car to the right of me moved off, and I heard someone beeping futher back so the combination of those things led me to believe the lights had turned green but they actually hadn't. The guy on my right hand side was obviously turning right and working to a different set of lights. In those few moments I incorrectly assumed the lights had turned green and moved over the line. Even so, all the other junctions I see have another set of lights set about 8 feet behind the line (helping those at the front to see the signals). At this junction, I would have to look out of the sunroof to see the lights. In hindsight I could have have stopped well before the line I suppose to help visibility of the traffic signals on the line but I wasn't considering the positions of these traffic signals on my approach to the lights. I guess I'll just have to wait and see if an NIP turns up. It's annoying though, the first time I go through a red light and there happens to be a camera on there. A better layout of the junction and the lights would obviously impinge on the revenue generation. If they can pay for a camera then surely they can pay for extra traffic signals to improve clarity (and safety).

I know what you mean about junction design. There is one near to me where an A road has a cross roads with a (now) one way street and a significant side road. The A road it splits into two lanes wide at this point (with a central barrier), and traffic on all of the roads is heavy at most times of day. Turning right onto the A road from one of the side roads involves crossing two lanes of traffic and the on-coming flow of traffic; if you don't move forward when the lights are green, you will never get across, so it is necessary to creep forward until you are adjacent with the road you want to go down (followed by all the other cars that are behind you) and hope for a break in the oncoming traffic. However from one direction there are no lights on the far side of the junction, so you cannot see when the oncoming traffic is getting a red light, and have to wait until it is obvious that they are stopping as opposed to just slowing to turn. The A road lights however go green about 3 seconds after the others go red, so the traffic on the A road is moving in many cases before the drivers trying to turn right even know that they are clear to go.

Every time I sit in that middle of that junction knowing that the traffic on either side of me is going to get a green while I haven't got a clue what is happening I swear at whatever type of idiot it was that decided I didn't need those extra few seconds notice that I could go. They did see fit to install red light cameras from both directions on the A road though, and with the barrier preventing use of the opposite lanes, it is exactly the sort of junction that drivers will need to move out of the way to allow emergency vehicles to get through. The fire station is less than a mile away, and commonly uses this road...

If I remember correctly, red light cameras only trigger if you're doing over 10 mph when you drive through -- this is to allow for slow moving queues of traffic when the road is gridlocked, and so forth.

orange

Is the 10mph rule true though? I didn't see a flash.

I'd heard they go off whether you cross the line at any speed, which seems to be what cam-op is saying. If that's right then maybe the lack of flash in your case is down to either a dummy camera or a faulty camera.

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Make everything as simple as possible, but not simpler - Einstein

Hey there

I have driven across the line when a light was red with a redlight camera behind me, I didn't accelerate hard, because I was following a que of traffic at sub-10mph all waiting to turn right at the junction.

Didn't get an NIP or even see a flash to be honest - but I'm not sure under what criteria these things are triggered off. My Dad, who was done for a TS10 many years ago reckons that the motion sensor on the lights which detect traffic is aware of how fast you are approaching the junction - and if approaching over a certain speed, it enables the redlight camera - if you then cross the lines - *flash*

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My friends call me RuFFy

Well, I haven't received a NIP yet. If I haven't received one by Sat 17th then I'm probably in the clear. Fingers crossed !

I didn't see a flash and only went over the line at around 5mph. Hopefully, the higher speed activation theory is correct.

Most traffic light sensors/red light triggers only detect a change in what they see so there must be some threshold for speed under which they won't detect you. This could be quite low though.

Seems a strange set up. I'm not saying you're wrong becuase I don't know, but I thought they had pressure sensors in the road and a control box that knew what colour the lights were. Certainly when red light cams were installed on a local junction some kind of sensor was installed in the road right before the line. I assume the way it works is that when the sensor detects someone passing it tells the control box which in turn tells the camera to ignore it if the lights are green or amber, or take a photo if the lights are red. If so, then it isn't going to care, or even know, what speed it was. I'm not saying that's gospel, merely my understanding. It would also seem uncharacteristically generous of the partnerships to allow a sufficiently low speed to avoid triggering a red light cam. I mean, given what they're usually like you'd expect them to set the things up so they flashed everyone who even sneezed across the line.

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Make everything as simple as possible, but not simpler - Einstein

These are known as "secondary" signals. You can have "far-sited/sighted" ones usually on the other side of the road or near sited/sighted which are (ridiculously) placed a minimum of 1m behind the primary signal.

The intention of secondaries as you say, is to improve sight of the signal head for those who deem it appropriate to stop too close to the line to see the signals, or if there is sunshine glare or whatever.



Ah, the old "bonus green" that some traffic engineers use to eke a few more seconds out of the signal cycle time.

Most designers will allow for the time it takes to clear a junction. The problem of course is that in off-peak hours, you have ridiculously long wait times between green signals on adjacent arms of the junction.

Australian ones certainly use the sensors, but then so do their lights - ie none of this red light on main road at 3am rubbish unless there's something on the minor road. It's always amusing outside Sydney uni to see bored students on pushbikes riding circles on the sensors to get their photo taken as often as possible before the lights change again.

My understanding from reading Pepipoo and other such sites is that after the lights go red therfe is a delay of at least 0.9s and then the camera is primed. Anyone caught going over the lines and therefore sensors after the camera has primed will have two photo's taken, the second to show the car has moved. From what I gather, and again I've read this from more then one source, their is a threshold speed of at least 10mph to avoid photos being taken when their is queing traffic and someone has legitamately gone through on green, found the other side is blocked and so stopped but after the line.

I can understand your point about not realising there were no secondary lights, it's very unusual that their isn't a set and so I probably wouldn't expect it. Of course there's no reason why you can't stop so you can see the primary set, but thats the benefit of hindsight!

to the forums by the way, you should stick around, plenty of interesting discussion on road safety!