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Old 08-05-2017, 05:06 PM   #1 (permalink)
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Green traffic lights?

The local traffic lights have variable timings (no sensors, countdown timers or visible pedestrian signals). And then there are lights you have never encountered before.
My question is, what is the best way to approach a green light?
If a light is red I hang back, hoping it will change, but I keep getting caught out on green lights, especially if they are already green when they first come into view. I never know whether to keep my speed up, hoping to reach them before they change, or slow down, expecting them to go red before I get there. I seem to make the wrong guess more often than I make the right one. I slow down, expecting them to change but they don't. But just before I reach them they do! If I had just kept going, when first I saw them, I'd have breezed through. Or I don't slow, then have to brake, wasting inertia and wasting fuel. Short of blowing off red lights I have no option.
Is there a technique for green lights? What do you experienced guys do?

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Old 08-05-2017, 05:40 PM   #2 (permalink)
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I've given up on green lights. I only make them when I don't expect I will.
I look for the loops cut in the tarmac, and lo and behold, no matter how many minutes the light has been green before, the very moment my car crosses the first of the traffic sensing loops it changes color.
If I would program traffic light computers I would stretch the cycle if traffic is approaching from the direction that has green, but it looks uncannily like the opposite is being done.

My advice:
If you are not in a hurry and not holding anyone up treat a green light as if it is red, let your car coast engine off etc. until you are close enough to pass it before it turns red even if it jumps to yellow right then.
- If it gets red before you're there you've done the right thing.
- If it stays green you had a nice P&G moment.
- If it gets red just before you arrive and you think you could have made it if you had kept pace, relax!
That light was waiting for you to make you miserable. You weren't going fast so you did not have to slam the brakes and waste a lot of fuel. You win and now the traffic light has a bad day. Maybe it remembers and betters its ways some day, who knows?

As it only stays green when I don't expect it, I try as hard as I can to not expect it.
It works quite well as long as you don't believe it does.
Once you do you'll only see reds despite your best efforts.
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Old 08-05-2017, 11:35 PM   #3 (permalink)
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We discussed stale green lights in our last driving class at work. It seem like they want you to pick a point of no return and approach at a normal speed. If you reach your point of no return and it changes you can get through on the yellow. They want you to look high and get the big picture as there is more to be seen. I have increased my following distances and made sure I had an out better after these classes.
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Old 08-06-2017, 01:38 AM   #4 (permalink)
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I've heard it's best to maintain speed (neither increase or decrease) if you don't know the timing of the light.
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Old 08-06-2017, 02:31 AM   #5 (permalink)
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Quote:
Originally Posted by JockoT View Post
The local traffic lights have variable timings (no sensors, countdown timers or visible pedestrian signals). And then there are lights you have never encountered before.
My question is, what is the best way to approach a green light?
With those kinds of lights, there isn't any good way. The best bad way is probably stay at constant speed, using as little throttle as possible, hope for the best but don't get your hopes up. I do okay on the lights that have the countdown timers and the few that are timed well, but in general, green lights are a crap shoot that I lose more than I win. One bad light makes a big difference to trip mileage on a short trip too. Very frustrating when they change the timing from one day to the next so you can't plan ahead.
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Old 08-06-2017, 05:11 AM   #6 (permalink)
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Before I started driving with fuel economy in mind I used the point of no return method. If there was someone fairly close behind I would normally touch my brakes, as I approached the green, just to let him know I am considering stopping. A driver following close behind would also influence my "point of no return". Mind you, I have slipped through a set of lights at my point of no return and had two or three vehicles follow me!
I like RedDevil's approach best. That's what I have tended to do. In future I just won't beat myself up when it fails.
Any other options out there?
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Old 08-06-2017, 06:54 AM   #7 (permalink)
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Some large citys have a, get you coming or going we dont cair attitude.
Lights green wave is set for rabbit starts(visable when you try to get back on the wave) and /or +5-15mph over speed limit(visable when trying to cross large citys like Las Vegas, NV). They get your money 1 buy more fuel to ride the wave and more tickets or,. 2 buy more fule stoping, idling (ac is needed in 100+F summers) , and takeoff at every light= more fule tax revenue that they dont spend on the road repairs.
---
Havent noticed the tomfoolery type yet , but probably will now that I heard of them. Solution time your cost down so that you have 5mph when it goes green. You may pass the sensor at 10 or less but whos in a hurry right.
---
?
Is it a lone ranger or the first of a string?
Lone ranger take it in stride expect it to be set for the predominant direction of travel /main road , hold steady (if it tomfooleries then take note for next time) if your on the secondary/ side street expect it will return to the primary, prepare to time your cost speed to include a red cycle, practice your tomfoolery tactics.
First in a string then its a game figuring out the pattern.
Time of day ? Some citys have different cycles for different secduals and/ or current conditions. Night helps to deduce if some one elce will trip and cycle the light before you can pass. If so cost and time the green before it even goes yellow .
My least favorite is Utahs flashing yellow unprotected left turns during rush hour that only go green arrow in middle of the night when your all alown andthe protection is un welcome have to stop and weight for the hole thing to cycle to you .
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Old 08-06-2017, 06:11 PM   #8 (permalink)
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A lot of lights here seem to be demand on cross traffic. I cant fathom the cycle because cross traffic is not visible to me. The sensor for my travel direction is too close to the light, so slowing down for the red is useless since it won't change the light.
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Old 08-07-2017, 01:42 AM   #9 (permalink)
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Quote:
Originally Posted by JockoT View Post
I have slipped through a set of lights at my point of no return and had two or three vehicles follow me!
I like RedDevil's approach best. That's what I have tended to do.
I know what you mean. I just sneak through yellow lights often, wondering if I made it before it turned red, just to see one or two more cars behind me that could have stopped for sure.
I often coast up to green lights that I think I may not make as well. I do it engine off though and it works well. I take the risk of trying to make the light when I can't EOC cause I think idling through the red light is worse. Then again, sometimes I miss and take a double hit. Choices, choices.
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Old 08-07-2017, 05:55 AM   #10 (permalink)
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While I reduce speed for a long green up ahead, there are lights I maintain speed towards when they are red - like those that have a fixed pattern of servicing the traffic directions, and I see cars crossing from the direction that gets green prior to my lane.
When it has just gone green and I can join up with the line of cars before the last car passed the lights I'll do that. Otherwise I coast.

When you know the pattern or traffic situation then you can work out when to brake and when to maintain speed.
If you do not know the pattern then you have to decide what you value most - time or fuel efficiency.
If missing a green you could have had worries you more than wasting fuel then maintain speed while it is still green. Otherwise coast towards the lights.

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