flashing your headlights at traffic lights ?
#4
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Some lights have light sensors I believe. There are a couple of sets down the road from me that I go through all the time and if you flash your full beams on approach when no one is on the other side then they change to green so you don't need to slow down.
Not all lights but some.
Cheers,
Tom
Not all lights but some.
Cheers,
Tom
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Most temporary lights have a speed sensor so if you slow too much(5-10mph iirc) they won't change. By not slowing down they will register your movement and change if nothing is coming the other way. There will be a maximum time for them to stay green on one side so that the continual movement doesn't mean you get stuck forever.
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#8
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And they're not temporary lights either.
Last edited by Torquemada; 12 June 2009 at 08:12 PM. Reason: added a bit
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As far as I know all lights now (around here anyways) work on sensors under the road. As you approach the lights you will normally see diamond or square shape repair lines in the road, thats where the sensors are buried.
Temporary lights have a motion sensor rather than a light sensor, the slower you approach temporary lights the more likely they are to change colour.
The services are exempt from traffic light signals so there is no need for them to have a special way to change the light phase.
Temporary lights have a motion sensor rather than a light sensor, the slower you approach temporary lights the more likely they are to change colour.
The services are exempt from traffic light signals so there is no need for them to have a special way to change the light phase.
#10
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Most temporary lights have a speed sensor so if you slow too much(5-10mph iirc) they won't change. By not slowing down they will register your movement and change if nothing is coming the other way. There will be a maximum time for them to stay green on one side so that the continual movement doesn't mean you get stuck forever.
Dave
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permanent lights near me respond to headlight flashes, but only during the middle of the night when its quiet and they're not on their auto mode (where every junction goes green in fixed order). At night, they just auto switch on detecting a car (normally before the car reaches any induction loops btw).
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The set at the entrance to my (country) estate go to red when the traffic is quiet.
So the baseball cap wearing dick-heads just drive at them expecting them to change....
which they won't do if I'm emerging at the T-junction.
Design by muppets imho !
dunx
So the baseball cap wearing dick-heads just drive at them expecting them to change....
which they won't do if I'm emerging at the T-junction.
Design by muppets imho !
dunx
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#17
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Seeing most traffic lights don't have microwave sensors (the little boxes ontop), And if they did, they work on mircowaves, not light; The same as automatic doors in shops
Most traffic lights however work on induction loops (the rectangular or diamond lines of tar that are embedded in the tarmac. Rolling to a 15mph crawl on the induction loops usually pokes them into action, so by the time you reach the light they flip to green.
Other lights are timed in sequence (usually on a main dual carriageway road in/out of a city with lots of cross roads. So sticking to a particular speed will guarantee hitting every light on green.
What is annoying is one stretch of road I know has a 40mph speed limit (with cameras); to get every light on green, one has to do 55mph (slowing to 40mph for the cameras). Sticking to the speed limit will mean every traffic light will change to red just as you reach it - sheer daftness done purely to impede traffic flow and increase fuel consumption
Most traffic lights however work on induction loops (the rectangular or diamond lines of tar that are embedded in the tarmac. Rolling to a 15mph crawl on the induction loops usually pokes them into action, so by the time you reach the light they flip to green.
Other lights are timed in sequence (usually on a main dual carriageway road in/out of a city with lots of cross roads. So sticking to a particular speed will guarantee hitting every light on green.
What is annoying is one stretch of road I know has a 40mph speed limit (with cameras); to get every light on green, one has to do 55mph (slowing to 40mph for the cameras). Sticking to the speed limit will mean every traffic light will change to red just as you reach it - sheer daftness done purely to impede traffic flow and increase fuel consumption
#18
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What is annoying is one stretch of road I know has a 40mph speed limit (with cameras); to get every light on green, one has to do 55mph (slowing to 40mph for the cameras). Sticking to the speed limit will mean every traffic light will change to red just as you reach it - sheer daftness done purely to impede traffic flow and increase fuel consumption
What is annoying is one stretch of road I know has a 40mph speed limit (with cameras); to get every light on green, one has to do 55mph (slowing to 40mph for the cameras). Sticking to the speed limit will mean every traffic light will change to red just as you reach it - sheer daftness done purely to impede traffic flow and increase fuel consumption
I remember in the early 80s I was despatch riding on a 750. You could catch all the greens on the Marlybone Road - but only if you were doing about 70 ... allegedly .... and very first thing in the morning before the traffic built up.
Dave
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What is annoying is one stretch of road I know has a 40mph speed limit (with cameras); to get every light on green, one has to do 55mph (slowing to 40mph for the cameras). Sticking to the speed limit will mean every traffic light will change to red just as you reach it - sheer daftness done purely to impede traffic flow and increase fuel consumption
#20
Flashing your lights does nothing, you might as well pat your head, or turn your hazards on.
Its no shock this happens at night. This is because the roads are very quiet.
What happens is you drive over a loop, the lights know there are no other cars (loops on the other side of the junction) and changes the lights for you. i.e priority mode. It just so happens you are flashing your lights at this point, you could be itching your **** and it would still do the same. (yes some lights have a little box on the top but this is just another way to detect the cars - some have loops, some have micro some have both).
This wont happen during busy times, you have to wait for the phased change, i.e wait your turn.
HGV drivers are (should be! LOL) trained to know this, they will often look for cars coming towards an TL junction from a side road so they will lift and brake as they know you are about to hit the loops before them and they will get a red light, so they slow for it anyway, then once your loop is clear they have slowed enough to make their lane go green again. Smooth driving style and saves fuel and time. Only works at night, but ask any overnight HGV driver and they will prob do it.
As for 999 priority, this does exist. However its often for a local problem. Most often for fire crews they will have a button in the cab that will give them a "green lane" near the station if they are in a very busy part of town.
There are also some places with keys on the actual control box, they (police) have the key and can turn the lights to red or green. Mainly used for large scale events etc to manage traffic.
HTH!!!
Its no shock this happens at night. This is because the roads are very quiet.
What happens is you drive over a loop, the lights know there are no other cars (loops on the other side of the junction) and changes the lights for you. i.e priority mode. It just so happens you are flashing your lights at this point, you could be itching your **** and it would still do the same. (yes some lights have a little box on the top but this is just another way to detect the cars - some have loops, some have micro some have both).
This wont happen during busy times, you have to wait for the phased change, i.e wait your turn.
HGV drivers are (should be! LOL) trained to know this, they will often look for cars coming towards an TL junction from a side road so they will lift and brake as they know you are about to hit the loops before them and they will get a red light, so they slow for it anyway, then once your loop is clear they have slowed enough to make their lane go green again. Smooth driving style and saves fuel and time. Only works at night, but ask any overnight HGV driver and they will prob do it.
As for 999 priority, this does exist. However its often for a local problem. Most often for fire crews they will have a button in the cab that will give them a "green lane" near the station if they are in a very busy part of town.
There are also some places with keys on the actual control box, they (police) have the key and can turn the lights to red or green. Mainly used for large scale events etc to manage traffic.
HTH!!!
#22
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Awwww, bless.
Well, that's interesting stuff, billy, thanks for the info.
There must be two loops per side on the set I'm talking about then, I've been snoped!
I'll drive at them tonight with my lights off to see what happens
Well, that's interesting stuff, billy, thanks for the info.
There must be two loops per side on the set I'm talking about then, I've been snoped!
I'll drive at them tonight with my lights off to see what happens
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I was fed up of getting stitched up in court by people getting paid more than me and having no PSD to investigate them..... So I thought I would move to the dark side, I used to lock em up, now I get em off.
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he did say this was on the night shift so guess the lights could be set differently after a certain time off day ??
agree that probably the majority off lights use the loop system now
Last edited by jono300; 14 June 2009 at 10:26 AM.
#26
I work as a courier at night it works on some lights you will notice some traffic lights have a sensor mounted on top off them have a look when you drive past this is the case when its dark not to sure in the day though
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The lights near the ambulance station in Plymouth do change if you flash your lights, it catches the flashing lights of the ambulance.
I appreciate not all lights doing this, what a sight it would be if everyone thought that by flashing your lights you would get through.
I appreciate not all lights doing this, what a sight it would be if everyone thought that by flashing your lights you would get through.
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funny as it sounds it works on most lights !!! It works around where im from mate.. only da odd few dont.. but yes they do, its a sign of police communication