# When Stoplights Don't Change **URL:** \ **Category:** Factual Questions\ **Created:** [December 29, 2009, 12:39pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899 "2009-12-29T12:39:02Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Strain\_of\_Thought](https://avatars.discourse-cdn.com/v4/letter/s/3be4f8/32.png) [@Strain\_of\_Thought](https://boards.straightdope.com/u/Strain_of_Thought)\ **Post date:** [December 29, 2009, 12:39pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/1 "2009-12-29T12:39:02Z")
I live in the state of Georgia in the US. I was on the road at four AM this morning, and I came to a red light. Shortly after I stopped, a new song began on the radio, one that I liked a lot and became engrossed in. When the song stopped and the light was still red, I realized I had been at the light for four minutes. This sort of thing has happened to me late at night several times before, often at the same lights as on previous occasions. For some reason, in the dead of night they just stop changing. On this occasion, I was able to back up into a different lane, then use a series of right-turns-on-red to get where I needed to go. But this has happened enough that I want to know two things: 1) Why does this sort of thing usually happen? 2) Legally, can I go after a certain time on such a light? What can I tell the police officer who happens to cruise up just as I give in to frustration and take my left turn on red? ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [December 29, 2009, 12:46pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/2 "2009-12-29T12:46:19Z")
The only thing that will be safe short term is to keep making those rights. You’ll have to prove the light was broken if you go straight or turn left and get caught. They are supposed to flash if the DOT decides not to enforce the traffic signals at certain times of the day. Report the incorrectly functioning lights. ---
**Author:** ![Pduol](https://avatars.discourse-cdn.com/v4/letter/p/6bbea6/32.png) [@Pduol](https://boards.straightdope.com/u/Pduol)\ **Post date:** [December 29, 2009, 12:48pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/3 "2009-12-29T12:48:11Z")
In answer to question one, there is an intersection near me where they set it up so that two cars have to be waiting at the red light in order for it to change. Maybe that’s what’s happening there. However, in the dead of night that particular light changes to a flashing one, so there never is really a problem. Other than that, I’ve got nothing. ---
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [December 29, 2009, 1:08pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/4 "2009-12-29T13:08:17Z")
> [@Strain\_of\_Thought](#): > > 1. Why does this sort of thing usually happen? 2) Legally, can I go after a certain time on such a light? What can I tell the police officer who happens to cruise up just as I give in to frustration and take my left turn on red? While it may be illegal technically to proceed, if it’s a trip light and the traffic detector is not working and you have stopped for a reasonable period of time, I’d just proceed and argue the ticket if I got one. The traffic detectors (usually an inductive wire loop in the pavement that acts like a metal detector, or else an over-road sensor of some type that detects a vehicle) can be defective and if the light is configured to only use the sensor, you’d be there a long time. I usually try backing up and re-tripping it but that’s about the extent of my patience. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [December 29, 2009, 1:38pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/5 "2009-12-29T13:38:33Z")
I would hope that it would fall under the category of “broken traffic control” and the intersection would revert to a 4 way stop. I couldn’t find this in a quick Google search, but I’m not awake yet. ---
**Author:** ![pan1](https://avatars.discourse-cdn.com/v4/letter/p/e495f1/32.png) [@pan1](https://boards.straightdope.com/u/pan1)\ **Post date:** [December 29, 2009, 2:08pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/6 "2009-12-29T14:08:33Z")
If you determine using reasonable rationality that the light is not functioning properly - you are legally required in most states to treat it like a stop sign. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [December 29, 2009, 3:01pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/7 "2009-12-29T15:01:50Z")
A left turn light on my shortest commute often does this to me, during the morning commute hour. I turn left on the red, which is difficult because it’s a major intersection and the cross road carries traffic at above its 50 mph speed limit. This was happening about weekly. I would usually call the state police barracks nearby and report it malfunctioning, but nobody ever fixed it. I asked a state trooper on the phone what I was supposed to do in this situation, and he hesitantly said if it were him he’d probably go through it like I did. It seems dangerous enough, though, that I added several miles to my commute to avoid this intersection. Seems a shame to do so, given how big a problem driving is for the environment, but the danger appears to me to be the bigger problem here. ---
**Author:** ![Dinsdale](https://avatars.discourse-cdn.com/v4/letter/d/97f17d/32.png) [@Dinsdale](https://boards.straightdope.com/u/Dinsdale)\ **Post date:** [December 29, 2009, 3:30pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/8 "2009-12-29T15:30:38Z")
Tough situation. Had something similar occur recently. Around 9 pm on a Wednesday I was on a smaller road, crossing a larger road at a controlled intersection. My light was green but turned yellow as I approached - being in no hurry I stopped and waited. I expected the cross light to be longer for the busier street (tho very few cars at the time), but as you did, I was surprised when my light stayed red well into the second song. Then a car approached the intersection heading towards me. The cross light turned yellow, so I got ready to go. But all that happened was that the guy facing me got a left turn arrow, while my light stayed red. Then it went back to the cross traffic getting another green. My patience was wearing thin at this point. I was thinking about blowing the red and risking the ticket, tho I was pretty sure there were no cops around. To be honest, the idea of turning right really didn’t occur to me. Fortunately, within another song or so, I finally got my green. A very frustrating situation to be sure. ---
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [December 29, 2009, 4:07pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/9 "2009-12-29T16:07:23Z")
It happens on my scooter sometimes because some of the lights go to sensors late at night and I don’t trigger them. They just passed a local ordinance allowing me to go ahead if I’ve waited a reasonable time and there’s nobody coming as long as I’m on a scooter or motorcycle. ---
**Author:** ![BobArrgh](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobarrgh/32/2881_2.png) [@BobArrgh](https://boards.straightdope.com/u/BobArrgh)\ **Post date:** [December 29, 2009, 4:25pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/10 "2009-12-29T16:25:11Z")
Left-turn lanes that are only tripped by the presence of a magnetic field are a bane of motorcyclists everywhere. When I am on my bike and encounter this situation, I will wait for one full rotation of the lights, and then will proceed on the next green light for the traffic going in my direction, as long as it is safe to do so. ---
**Author:** ![Rhythmdvl](https://avatars.discourse-cdn.com/v4/letter/r/85f322/32.png) [@Rhythmdvl](https://boards.straightdope.com/u/Rhythmdvl)\ **Post date:** [December 29, 2009, 5:14pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/11 "2009-12-29T17:14:59Z")
Depending on traffic conditions, you should do between one and four doughnuts in the intersection before proceeding with caution. ---
**Author:** ![Rumor\_Watkins](https://avatars.discourse-cdn.com/v4/letter/r/d9b06d/32.png) [@Rumor\_Watkins](https://boards.straightdope.com/u/Rumor_Watkins)\ **Post date:** [December 29, 2009, 5:17pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/12 "2009-12-29T17:17:06Z")
> [@BobArrgh](#): > > Left-turn lanes that are only tripped by the presence of a magnetic field are a bane of motorcyclists everywhere. Bicyclists have it worse. Much. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [December 29, 2009, 5:27pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/13 "2009-12-29T17:27:07Z")
> [@Telemark](#): > > I would hope that it would fall under the category of “broken traffic control” and the intersection would revert to a 4 way stop. I couldn’t find this in a quick Google search, but I’m not awake yet. > [@pan1](#): > > If you determine using reasonable rationality that the light is not functioning properly - you are legally required in most states to treat it like a stop sign. Traffic lights that are completely out (no power) are supposed to be treated as a 4-way stop. (Around here, they are treated as a free-for-all.) However, if you go through a traffic light that is on and just not changing, watch out for the guys who have green. _They_ don’t think it’s malfunctioning and they are certainly not going to stop. ---
**Author:** ![HeyHomie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heyhomie/32/207_2.png) [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)\ **Post date:** [December 29, 2009, 9:39pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/14 "2009-12-29T21:39:11Z")
[http://www.mestodesign.com/wp-content/uploads/2009/10/this\_light\_never\_turns\_green.jpg](http://www.mestodesign.com/wp-content/uploads/2009/10/this_light_never_turns_green.jpg) ---
**Author:** ![Ignatz](https://avatars.discourse-cdn.com/v4/letter/i/3be4f8/32.png) [@Ignatz](https://boards.straightdope.com/u/Ignatz)\ **Post date:** [December 29, 2009, 11:12pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/15 "2009-12-29T23:12:24Z")
Normally the magnetic loop vehicle detector is placed behind the left turn lane stop line. The detector may be set in either a “pulse” mode that keeps the call once you go over it, or it may be in “presence” mode which requires the vehicle to be over it to activate it. If you pull up past the stop line in presence mode you may have become undetected. The detector amplifier may be kaput. Call the govermental jurisdiction that handles signal maintenance there and report it, being specific on the location (direction, which lane) and the time of the observation. ---
**Author:** ![Magicicada](https://avatars.discourse-cdn.com/v4/letter/m/c67d28/32.png) [@Magicicada](https://boards.straightdope.com/u/Magicicada)\ **Post date:** [December 30, 2009, 1:05am UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/16 "2009-12-30T01:05:54Z")
> [@Zsofia](#): > > It happens on my scooter sometimes because some of the lights go to sensors late at night and I don’t trigger them. They just passed a local ordinance allowing me to go ahead if I’ve waited a reasonable time and there’s nobody coming as long as I’m on a scooter or motorcycle. 🆒 I’m impressed. I’ve never had them pass any local ordinances for me. ---
**Author:** ![Tamex](https://avatars.discourse-cdn.com/v4/letter/t/ccd318/32.png) [@Tamex](https://boards.straightdope.com/u/Tamex)\ **Post date:** [December 30, 2009, 1:10am UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/17 "2009-12-30T01:10:02Z")
> [@Rumor\_Watkins](#): > > Bicyclists have it worse. Much. I generally use the “push here to cross” button meant for pedestrians when I ride my bike. ---
**Author:** ![Dusty\_Rose](https://avatars.discourse-cdn.com/v4/letter/d/ba8739/32.png) [@Dusty\_Rose](https://boards.straightdope.com/u/Dusty_Rose)\ **Post date:** [December 30, 2009, 1:12am UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/18 "2009-12-30T01:12:30Z")
> [@Ignatz](#): > > Normally the magnetic loop vehicle detector is placed behind the left turn lane stop line. The detector may be set in either a “pulse” mode that keeps the call once you go over it, or it may be in “presence” mode which requires the vehicle to be over it to activate it. If you pull up past the stop line in presence mode you may have become undetected. The detector amplifier may be kaput. Call the govermental jurisdiction that handles signal maintenance there and report it, being specific on the location (direction, which lane) and the time of the observation. I am always so impressed by the knowledge around here! As to the OP, I’d back up and try to re-trigger it. If that didn’t work, I’d go through it. The only way I’d do a series of rights is if there’s tons of traffic. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [December 30, 2009, 7:45am UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/19 "2009-12-30T07:45:47Z")
> [@Tamex](#): > > I generally use the “push here to cross” button meant for pedestrians when I ride my bike. If there’s an induction loop, you can often trigger it with your bike. I do it frequently. First you have to find the loop. Look for a black circle about 4 or 5 feet in diameter near the head of the lane. If they put the loop in after the road was paved, they’ll will have cut a narrow circular trench to put it in. After loop installation, the trench is sealed with tar, making a black circle. Put the wheel of your bike directly on that black line. Leave it there until you get a green. It won’t always work. There’s a couple intersections this area where it doesn’t work. In other intersections they installed the loop before paving, so there’s no circle. These can sometimes be triggered by laying the bike down on its side so that some metal part is (hopefully) laying close enough to the loop to trigger it. I don’t do this very often. Older loops were in a diamond shape rather than circular. These are getting quite rare, but there’s at least one still working in this area. Put your bike wheel on one of the black lines that make up the diamond to trigger. Don’t know if this works for motorcycles, but probably does. ---
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [December 30, 2009, 12:52pm UTC](https://boards.straightdope.com/t/when-stoplights-dont-change/522899/20 "2009-12-30T12:52:16Z")
> [@BobArrgh](#): > > Left-turn lanes that are only tripped by the presence of a magnetic field are a bane of motorcyclists everywhere. When I am on my bike and encounter this situation, I will wait for one full rotation of the lights, and then will proceed on the next green light for the traffic going in my direction, as long as it is safe to do so. For $25 or so you can buy a trigger. I have no idea how well they work, but I have heard of them. [http://www.greenlightstuff.com/trigger.html](http://www.greenlightstuff.com/trigger.html) [Next page](https://boards.straightdope.com/t/when-stoplights-dont-change/522899.md?page=2)