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Post by the light works on Jul 15, 2017 21:36:05 GMT
yes, on my way home today, I hit multiple sets of red lights, and I noticed a pattern. if I hit one light red, then there would be a gap in front of me, and the next light would turn red when that gap reached it. that made me wonder if, in the case of "demand" lights, which change depending on traffic conditions instead of a timer; (yes, I know in some towns, the traffic lights through town are timed such that if you drive at the speed limit, you will hit every light at the same point in its cycle - I'm not talking about those lights) in certain traffic conditions, the traffic pattern WILL cause the poor dumb bar-steward who gets caught at one red light, to get caught at every red light the rest of the way through town.
may not be a show-worthy idea, but it was an interesting observation.
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Post by GTCGreg on Jul 15, 2017 23:31:57 GMT
yes, on my way home today, I hit multiple sets of red lights, and I noticed a pattern. if I hit one light red, then there would be a gap in front of me, and the next light would turn red when that gap reached it. that made me wonder if, in the case of "demand" lights, which change depending on traffic conditions instead of a timer; (yes, I know in some towns, the traffic lights through town are timed such that if you drive at the speed limit, you will hit every light at the same point in its cycle - I'm not talking about those lights) in certain traffic conditions, the traffic pattern WILL cause the poor dumb bar-steward who gets caught at one red light, to get caught at every red light the rest of the way through town. may not be a show-worthy idea, but it was an interesting observation. The smart "demand" lights are only as smart as the guy that programmed them. And he probably doesn't live anywhere near there so why should he care?
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Post by the light works on Jul 15, 2017 23:50:57 GMT
yes, on my way home today, I hit multiple sets of red lights, and I noticed a pattern. if I hit one light red, then there would be a gap in front of me, and the next light would turn red when that gap reached it. that made me wonder if, in the case of "demand" lights, which change depending on traffic conditions instead of a timer; (yes, I know in some towns, the traffic lights through town are timed such that if you drive at the speed limit, you will hit every light at the same point in its cycle - I'm not talking about those lights) in certain traffic conditions, the traffic pattern WILL cause the poor dumb bar-steward who gets caught at one red light, to get caught at every red light the rest of the way through town. may not be a show-worthy idea, but it was an interesting observation. The smart "demand" lights are only as smart as the guy that programmed them. And he probably doesn't live anywhere near there so why should he care? well, if we never thought of it before, why would you expect a traffic light engineer to?
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Post by ironhold on Jul 15, 2017 23:59:05 GMT
Well, one thing to look at is what's governing the lights.
Some lights are governed by traffic cameras, while others are governed by pressure plates. In the case of the latter, a plate that's not sensitive enough or a vehicle that's too light will result in the plate not reading. There are a couple of intersections here in town I try to avoid if there's no other traffic since my car doesn't always set off the plate.
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Post by the light works on Jul 16, 2017 1:34:22 GMT
Well, one thing to look at is what's governing the lights. Some lights are governed by traffic cameras, while others are governed by pressure plates. In the case of the latter, a plate that's not sensitive enough or a vehicle that's too light will result in the plate not reading. There are a couple of intersections here in town I try to avoid if there's no other traffic since my car doesn't always set off the plate. here, we have one camera controlled light, and I know of one light that had a pressure plate as of the last time I saw it - in the 90s. the rest use induction coils. but that is beside the point. the point is the software typically defines one street as the through street and the other as the side street - when the light registers a car waiting on the side street, it will start a timer - if it registers a gap in traffic on the main street, it will switch the light, early, but otherwise, it will still switch the light when the timer runs out. so a person going through town on the through street, if he gets caught by a red light in moderate traffic, will always have a gap in traffic ahead of him - hence, the light will change before he gets to the sensor, if there is someone waiting on the side street. - and he will continue getting caught by the red light.
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Post by Cybermortis on Jul 16, 2017 1:43:14 GMT
Normally I'd consider the difficulty of actually testing this to be a problem, especially since there seems to be so many different traffic control systems in use. Plus any testing would be limited to the local area and might not be viable elsewhere.
In this case however mobile traffic lights would be easy enough to borrow, and I'd assume it would be easy to change their timing to mimic different traffic conditions and systems.
I'm also thinking that it make things more interesting they could do such a traffic myth using go-karts (which means a smaller test area) and maybe bring in some kids as drivers.
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Post by the light works on Jul 16, 2017 1:56:07 GMT
Normally I'd consider the difficulty of actually testing this to be a problem, especially since there seems to be so many different traffic control systems in use. Plus any testing would be limited to the local area and might not be viable elsewhere. In this case however mobile traffic lights would be easy enough to borrow, and I'd assume it would be easy to change their timing to mimic different traffic conditions and systems. I'm also thinking that it make things more interesting they could do such a traffic myth using go-karts (which means a smaller test area) and maybe bring in some kids as drivers. easy enough to make traffic lights.
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Post by Cybermortis on Jul 16, 2017 2:40:08 GMT
Easier and faster to hire lights than waste time building something they then have taking up storage space. They would also be able to hire far more lights than they could build in the time available; Remember that they would have 7-10 days for building and testing, and the less time they spend on one myth the more time they can spend on something else*
Building lights would require building a variable timing system for a network, and if MB history has taught us anything its that such complex systems have a nasty tendency to stop working as soon as the camera is pointed in its general direction. They might still have to design such a system, but at least they would be able to focus on that rather than worry about building a dozen lighting rigs.
(*A rough estimate in this case would be 7 days, with three on location - One to set up, one to film and a 'spare' day in case they go over schedule. That would leave them with only four days to build everything for what is likely to be considered to be a secondary story)
Note; I am basing my estimates and thinking on information provided by the Bothan as well as the not unreasonable assumption that they have the exact same limitations as the original run of the show. Meaning its best to consider the cheapest and fastest way to test something as this is more likely to result in a Myth being put on a list of potential stories. I do actually like this particular myth since, while it was your observation, it is a common complaint even here in the UK that if you have the misfortune to hit one red light you'll end up hitting most of them. There are also several ways it could be tested, from driving the streets to getting kids involved. It also doesn't have to be that expensive or time consuming if they don't want it to be.
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Post by the light works on Jul 16, 2017 3:31:11 GMT
Easier and faster to hire lights than waste time building something they then have taking up storage space. They would also be able to hire far more lights than they could build in the time available; Remember that they would have 7-10 days for building and testing, and the less time they spend on one myth the more time they can spend on something else* Building lights would require building a variable timing system for a network, and if MB history has taught us anything its that such complex systems have a nasty tendency to stop working as soon as the camera is pointed in its general direction. They might still have to design such a system, but at least they would be able to focus on that rather than worry about building a dozen lighting rigs. (*A rough estimate in this case would be 7 days, with three on location - One to set up, one to film and a 'spare' day in case they go over schedule. That would leave them with only four days to build everything for what is likely to be considered to be a secondary story) Note; I am basing my estimates and thinking on information provided by the Bothan as well as the not unreasonable assumption that they have the exact same limitations as the original run of the show. Meaning its best to consider the cheapest and fastest way to test something as this is more likely to result in a Myth being put on a list of potential stories. I do actually like this particular myth since, while it was your observation, it is a common complaint even here in the UK that if you have the misfortune to hit one red light you'll end up hitting most of them. There are also several ways it could be tested, from driving the streets to getting kids involved. It also doesn't have to be that expensive or time consuming if they don't want it to be. all of the mobile traffic light systems I have seen are to replace flaggers on roads that have become one lane traffic. however, they would probably be able to get software for common logic controllers that matches the common stoplight programming. and from there it is just a matter of getting a sensor that works with their vehicles - if you do a one way grid, a simple electric eye would work.
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Post by GTCGreg on Jul 16, 2017 4:26:29 GMT
The traffic lights on the main streets in our town are all tied into a central computer at the department of public works building. They can monitor the actual traffic flow through each intersection and the computer sets the pattern of all of the lights along that section of roadway. I don't know who did the programming but there was a noticeable decrease in congestion at the intersections after they turned on the system. If there is a disruption in the communication system the traffic lights can revert to Autonomous operation.
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Post by the light works on Jul 16, 2017 13:52:47 GMT
The traffic lights on the main streets in our town are all tied into a central computer at the department of public works building. They can monitor the actual traffic flow through each intersection and the computer sets the pattern of all of the lights along that section of roadway. I don't know who did the programming but there was a noticeable decrease in congestion at the intersections after they turned on the system. If there is a disruption in the communication system the traffic lights can revert to Autonomous operation. our midtown lights were originally timed to 30 MPH. later, they got the idea to add a sensor on the side streets, so if nobody was waiting, they would not go red for the through street, now, I notice, there is no timer.
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Post by GTCGreg on Jul 16, 2017 13:59:17 GMT
What really messes things up is when an emergency vehicle goes through and trips the lights. It seems to take three or four cycles for the lights to get back to their normal patterns.
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Post by the light works on Jul 16, 2017 15:35:24 GMT
What really messes things up is when an emergency vehicle goes through and trips the lights. It seems to take three or four cycles for the lights to get back to their normal patterns. I would guess that is because the emergency vehicle disrupts the traffic pattern enough to confuse the adaptive programming. our training officer was on an air force base in Germany, and he said in the town that was in, the lights had central control, and in a fire response, the entire fire fleet would convoy from the station, and the central control would override ALL of the lights between the station and the fire - so the fire crew had a solid line of green until they got to the fire. here, each light has an individual sensor, and each apparatus has a transmitter that trips the sensor to preempt the light. it is useful since we can come from any direction, but it is also less reliable. a note on camera controlled lights - when they installed our camera controlled light, they did not have it adjusted properly, and it would see a car coming on the side street and set its programmed cycle to let the car in - but if the car made a legal right-on-red turn (allowed, here) the program would not recognize the car was no longer there, and it would still cycle the light.
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Post by ironhold on Jul 16, 2017 18:13:06 GMT
I just remembered an old, mostly forgotten crime drama called "Nash Bridges". en.wikipedia.org/wiki/List_of_Nash_Bridges_episodesAn episode of the series (#15, season 6) involved Nash and his team having to protect a key witness who was something of a hustler. As part of it, he bet Nash & co. that they couldn't make 10 green lights in a row. Nash responded by revealing that his vehicle had a device which would let him override the lights so that they could go straight through. Does such a device exist in real life?
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Post by ponytail61 on Jul 16, 2017 21:04:51 GMT
I just remembered an old, mostly forgotten crime drama called "Nash Bridges". en.wikipedia.org/wiki/List_of_Nash_Bridges_episodesAn episode of the series (#15, season 6) involved Nash and his team having to protect a key witness who was something of a hustler. As part of it, he bet Nash & co. that they couldn't make 10 green lights in a row. Nash responded by revealing that his vehicle had a device which would let him override the lights so that they could go straight through. Does such a device exist in real life? I believe it's called the Opticom System.
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Post by the light works on Jul 16, 2017 21:35:50 GMT
I just remembered an old, mostly forgotten crime drama called "Nash Bridges". en.wikipedia.org/wiki/List_of_Nash_Bridges_episodesAn episode of the series (#15, season 6) involved Nash and his team having to protect a key witness who was something of a hustler. As part of it, he bet Nash & co. that they couldn't make 10 green lights in a row. Nash responded by revealing that his vehicle had a device which would let him override the lights so that they could go straight through. Does such a device exist in real life? yes, it is called Opticomm. it uses a strobe to send a signal to a receiver on the traffic light. originally, it was a true strobe, but now they use LED strobes - and some models use infrared LEDs. of course, the light has to be set up for it, or it doesn't work. (needless to say, it illegal for civilian use in most places)
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Post by silverdragon on Jul 25, 2017 9:29:28 GMT
I just remembered an old, mostly forgotten crime drama called "Nash Bridges". en.wikipedia.org/wiki/List_of_Nash_Bridges_episodesAn episode of the series (#15, season 6) involved Nash and his team having to protect a key witness who was something of a hustler. As part of it, he bet Nash & co. that they couldn't make 10 green lights in a row. Nash responded by revealing that his vehicle had a device which would let him override the lights so that they could go straight through. Does such a device exist in real life? Over here, they used in-the-road sensors to gauge the length of the que, you can see diamond shaped patterns cut into the road on many junctions, that have inductive loop type sensing. If an emergency vehicle approaches that inductive loop, it can send a "Radio message" by interfering with the usual sensing of that loop, and that "Coded" message something like Morse code, would be recognised by the sensing equipment, and alter the lights to full red in all directions, and then allow a green to move traffic and allow the emergency vehicle to pass. I am being deliberately inaccurate in the actual way that works, because I dont want some "Smart-[donkey]" lurker to read this and try to recreate the technology used.... But I do know that emergency vehicles have a sort of radar sender pointing down and forwards to send that message to the inductive loop to "let me through" kind of thing. Other systems in use, there are many, this below wiki is just one... en.wikipedia.org/wiki/Traffic_signal_preemption
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Post by GTCGreg on Jul 25, 2017 12:58:57 GMT
All of the systems around here are either optically-based or work off an RF transmitter in the emergency vehicle. They trigger the lights at least a half mile in advance. Waiting until the emergency vehicle hits the inductive loops is a little too late to be effective.
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Post by silverdragon on Jul 26, 2017 8:59:02 GMT
I am guessing that in a busy city with lots of traffic camera's like Manchester, we have a system in the more crowded parts that can "Clear a lane" a little ahead of just the induction loops, they would just need to talk to control and get them a passage?.
However...
Its always known that Junctions are the worst places for accidents with emergency vehicles. In Driver Training for fast pursuit, all the drivers are told, if you crash at speed, its YOUR bloody fault, there is no "Free pass" for driving blue-and-two, so they are taught to slow the hell down and check each junction and not presume its clear for them.
There is a whole world of difference between driving fast and getting there... any fool can hit the loud pedal, its what you do afterwards that matters?.
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Post by the light works on Jul 26, 2017 15:04:45 GMT
I am guessing that in a busy city with lots of traffic camera's like Manchester, we have a system in the more crowded parts that can "Clear a lane" a little ahead of just the induction loops, they would just need to talk to control and get them a passage?. However... Its always known that Junctions are the worst places for accidents with emergency vehicles. In Driver Training for fast pursuit, all the drivers are told, if you crash at speed, its YOUR bloody fault, there is no "Free pass" for driving blue-and-two, so they are taught to slow the hell down and check each junction and not presume its clear for them. There is a whole world of difference between driving fast and getting there... any fool can hit the loud pedal, its what you do afterwards that matters?. trying to use the induction loop for an antenna for the preemption signal seems like doing things the hard way to me. especially when you could mount a directional antenna above the road surface and have it plugged into its own receiver.
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