# Force a Green Light by reverse & rollback? **URL:** \ **Category:** Factual Questions\ **Created:** [November 27, 2004, 1:15am UTC](https://boards.straightdope.com/t/force-a-green-light-by-reverse-rollback/276812 "2004-11-27T01:15:09Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [November 28, 2004, 9:46pm UTC](https://boards.straightdope.com/t/force-a-green-light-by-reverse-rollback/276812/21 "2004-11-28T21:46:24Z")
I’ve done it and it works. If any one is interested email me and I will give you the intersection in NY-LI area of one I know works, each and every time. ---
**Author:** ![Mbossa](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@Mbossa](https://boards.straightdope.com/u/Mbossa)\ **Post date:** [November 28, 2004, 11:31pm UTC](https://boards.straightdope.com/t/force-a-green-light-by-reverse-rollback/276812/22 "2004-11-28T23:31:15Z")
I’ve found (YMMV etc) that pressing the walk button on a deserted set of lights _always_ forces the lights to go through a cycle, even if they were originally in the right state for letting the pedestrian cross. So if you come up to a set of lights that won’t change, you could hop out, press any button, hop back in, and await victory. ---
**Author:** ![Declan](https://avatars.discourse-cdn.com/v4/letter/d/ecae2f/32.png) [@Declan](https://boards.straightdope.com/u/Declan)\ **Post date:** [November 28, 2004, 11:57pm UTC](https://boards.straightdope.com/t/force-a-green-light-by-reverse-rollback/276812/23 "2004-11-28T23:57:59Z")
> [@Sunspace](#): > > In Toronto a few sesnsor-equiped intersections have three white dots over part of the sensor. Cyclists are supposed to halt their bikes over those dots and the sensor will detect the\*\* bile\*\*. Never ride bikes in toronto , a perfect example of too much information gathered for some ilicit purpose 😃 Declan ---
**Author:** ![Kiminy](https://avatars.discourse-cdn.com/v4/letter/k/6a8cbe/32.png) [@Kiminy](https://boards.straightdope.com/u/Kiminy)\ **Post date:** [November 29, 2004, 12:01am UTC](https://boards.straightdope.com/t/force-a-green-light-by-reverse-rollback/276812/24 "2004-11-29T00:01:01Z")
I was visiting my brother in a small college town in Illinois last weekend, and I noticed large signs at many intersections that said “Stop HERE to force light change” (or something along those lines). Apparently there are lots of people in that area who stop too far away from the sensors and complain about lights never changing for them… When I was in high school, my father drove a Lotus Europa that had a fiberglass body. There were lots of lights that it wouldn’t trip, so he just drove through empty intersections on red lights rather than wait forever. ---
**Author:** ![Vlad\_Igor](https://avatars.discourse-cdn.com/v4/letter/v/7feea3/32.png) [@Vlad\_Igor](https://boards.straightdope.com/u/Vlad_Igor)\ **Post date:** [November 29, 2004, 1:03am UTC](https://boards.straightdope.com/t/force-a-green-light-by-reverse-rollback/276812/25 "2004-11-29T01:03:31Z")
> [@Chronos](#): > > So aluminum (which is a better conducter than iron) will work just fine, and one of those fancy-schmancy superconducting ceramics would work better than either (if you don’t mind carrying a liquid nitrogen system on your bike). I usedta work with traffic engineers, so I learned how the loop detectors worked. Being the law-abiding bike rider that I am, I wanted to be able to trip left-turn signals. I sawed off a two-foot section of a broom handle, and fastened two donut magnets on the end, and attached the whole thing to the vertical support of my bike. All I had to do was unclip it and wave it over the wire loop to trip the light. It was also useful for bonking chasing dogs on the nose. Vlad/Igor ---
**Author:** ![Elvez](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@Elvez](https://boards.straightdope.com/u/Elvez)\ **Post date:** [November 29, 2004, 1:13am UTC](https://boards.straightdope.com/t/force-a-green-light-by-reverse-rollback/276812/26 "2004-11-29T01:13:15Z")
> [@Mbossa](#): > > I’ve found (YMMV etc) that pressing the walk button on a deserted set of lights _always_ forces the lights to go through a cycle, even if they were originally in the right state for letting the pedestrian cross. So if you come up to a set of lights that won’t change, you could hop out, press any button, hop back in, and await victory. This works if you’re going straight, but if you’re waiting for a left turn arrow, you can still get skipped. I think traffic light cycles only give a turn arrow when there’s a car in the turn lane, not when the pedestrian button is pushed. [Previous page](https://boards.straightdope.com/t/force-a-green-light-by-reverse-rollback/276812.md?page=1)