# Flashing brights at traffic lights

**URL:** <https://boards.straightdope.com/t/flashing-brights-at-traffic-lights/183477>\
**Category:** Factual Questions\
**Created:** [June 21, 2003, 9:16pm UTC](https://boards.straightdope.com/t/flashing-brights-at-traffic-lights/183477 "2003-06-21T21:16:47Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![Greekigurli](https://avatars.discourse-cdn.com/v4/letter/g/df705f/32.png) [@Greekigurli](https://boards.straightdope.com/u/Greekigurli)\
**Post date:** [June 21, 2003, 9:16pm UTC](https://boards.straightdope.com/t/flashing-brights-at-traffic-lights/183477/1 "2003-06-21T21:16:47Z")

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How did some people come to believe that flashing their bright lights while at a red light will make the light change to green? If we went by this logic then the light would never turn green for those who didn’t flash their lights.

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**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\
**Post date:** [June 21, 2003, 9:26pm UTC](https://boards.straightdope.com/t/flashing-brights-at-traffic-lights/183477/2 "2003-06-21T21:26:45Z")

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[Will flicking headlights change traffic lights from red to green?](http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=121888)

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**Author:** ![Thaumaturge](https://avatars.discourse-cdn.com/v4/letter/t/858c86/32.png) [@Thaumaturge](https://boards.straightdope.com/u/Thaumaturge)\
**Post date:** [June 21, 2003, 9:29pm UTC](https://boards.straightdope.com/t/flashing-brights-at-traffic-lights/183477/3 "2003-06-21T21:29:54Z")

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Are your brights on?  
Maybe they’re just signaling to you to turn off _your_ brights, which are shining in their faces. I’ve done that to people who have their brights on at traffic signals. I’ve never seen anyone do it to me though, since I never drive with my brights on where they’d be directed at another vehicle.

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**Author:** ![Thaumaturge](https://avatars.discourse-cdn.com/v4/letter/t/858c86/32.png) [@Thaumaturge](https://boards.straightdope.com/u/Thaumaturge)\
**Post date:** [June 21, 2003, 9:31pm UTC](https://boards.straightdope.com/t/flashing-brights-at-traffic-lights/183477/4 "2003-06-21T21:31:50Z")

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Upon reading the link. there are apparently people who beleive this is so, mindboggling.

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**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\
**Post date:** [June 21, 2003, 9:47pm UTC](https://boards.straightdope.com/t/flashing-brights-at-traffic-lights/183477/5 "2003-06-21T21:47:33Z")

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I knew someone who used to do this - trouble is, it is one of those self-reinforcing myths:

One of two things can happen when you drive up to the signals and flash your lights(believing that it works):  
1: The lights change within a short space of time (but completely by coincidence or because the microwave doppler module or buried loop detected your car approaching) - you say to your passenger “See, I told you it works”  
2: The lights do not change within a short space of time - you say to your passenger “Bloody thing must be broken”

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**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\
**Post date:** [June 21, 2003, 9:59pm UTC](https://boards.straightdope.com/t/flashing-brights-at-traffic-lights/183477/6 "2003-06-21T21:59:43Z")

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> [@](#):
>
> I knew someone who used to do this - trouble is, it is one of those self-reinforcing myths:

Sort of like those people who push the crosswalk button endlessly.

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**Author:** ![Violet](https://avatars.discourse-cdn.com/v4/letter/v/ebca7d/32.png) [@Violet](https://boards.straightdope.com/u/Violet)\
**Post date:** [June 21, 2003, 10:03pm UTC](https://boards.straightdope.com/t/flashing-brights-at-traffic-lights/183477/7 "2003-06-21T22:03:09Z")

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> [@](#):
>
> \*Originally posted by Johnny L.A. \*  
> \*\*Sort of like those people who push the crosswalk button endlessly. \*\*

Or elevator buttons! :rolleyes:

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**Author:** ![Greekigurli](https://avatars.discourse-cdn.com/v4/letter/g/df705f/32.png) [@Greekigurli](https://boards.straightdope.com/u/Greekigurli)\
**Post date:** [June 22, 2003, 8:01am UTC](https://boards.straightdope.com/t/flashing-brights-at-traffic-lights/183477/8 "2003-06-22T08:01:07Z")

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LOL These people also fail to realize, what happens when it’s daylight and there are no headlights? How will the headlight sensors know when to change the signal light then?!?! LOL