# Boxes Next to some Traffic Lights
**URL:** https://boards.straightdope.com/t/boxes-next-to-some-traffic-lights/532617
**Category:** Factual Questions
**Created:** [March 16, 2010, 2:39am UTC](https://boards.straightdope.com/t/boxes-next-to-some-traffic-lights/532617 "2010-03-16T02:39:12Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Jinx](https://boards.straightdope.com/u/Jinx)
#### Post date: [March 16, 2010, 2:39am UTC](https://boards.straightdope.com/t/boxes-next-to-some-traffic-lights/532617/1 "2010-03-16T02:39:12Z")
More and more, I see these “boxes” mounted beside the traffic light. They look like they could flash a short message, or perhaps flash “CAUTION” or something? They look a bit bigger than the electronic “X” sign used to denote reversable lanes. Does anyone have a clue what these are? I will say these have surfaced in the last year, at best.
---
### Author:  [@Stan\_Shmenge](https://boards.straightdope.com/u/Stan_Shmenge)
#### Post date: [March 22, 2010, 3:23am UTC](https://boards.straightdope.com/t/boxes-next-to-some-traffic-lights/532617/2 "2010-03-22T03:23:12Z")
Could be to flash “No Left Turn” during peak hours. We have these here now in LA.
---
### Author:  [@10913](https://boards.straightdope.com/u/10913)
#### Post date: [March 22, 2010, 3:25am UTC](https://boards.straightdope.com/t/boxes-next-to-some-traffic-lights/532617/3 "2010-03-22T03:25:34Z")
> [@Stan\_Shmenge](#):
>
> Could be to flash “No Left Turn” during peak hours. We have these here now in LA.
Ditto this; these signs are all over downtown Milwaukee as well.
---
### Author:  [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)
#### Post date: [March 23, 2010, 10:45pm UTC](https://boards.straightdope.com/t/boxes-next-to-some-traffic-lights/532617/4 "2010-03-23T22:45:12Z")
If your state allows turning right on red they could be electronic signs prohibiting this (i.e. No Turn On Red signs) at certain times.