AARoads Forum

National Boards => General Highway Talk => Traffic Control => Topic started by: TheArkansasRoadgeek on November 14, 2017, 09:31:05 PM

Title: What are these?
Post by: TheArkansasRoadgeek on November 14, 2017, 09:31:05 PM
So I though these (https://www.google.com/maps/@34.7881109,-92.2813342,3a,15y,315.74h,91.65t/data=!3m6!1e1!3m4!1smFzGd3aiuyqmwOIY-WBvXA!2e0!7i13312!8i6656) (the boxes) were prohibiting left/right turn LED setups, but judging from other photos, maybe not. They seem way small for the size of such arrows that are used. They could be receivers, Van Buren has one on a mast facing Main St. It looks like something that would light up, but I guess not.
Title: Re: What are these?
Post by: GaryV on November 14, 2017, 09:36:43 PM
Maybe sensors for emergency vehicles, so the light changes to green for them?  As I recall, it works on some kind of coded signals, microwave or infrared, proprietary to the police and fire.
Title: Re: What are these?
Post by: TheArkansasRoadgeek on November 14, 2017, 10:05:21 PM
Quote from: GaryV on November 14, 2017, 09:36:43 PM
Maybe sensors for emergency vehicles, so the light changes to green for them?  As I recall, it works on some kind of coded signals, microwave or infrared, proprietary to the police and fire.
Couldn't they just use an antenna?

Also, I thought they were blackout boxes, But I saw several in a recent thread that were much larger. interesting... :hmmm:
Title: Re: What are these?
Post by: Mdcastle on November 14, 2017, 10:40:35 PM
IR receivers for emergency vehicle pre-emption look nothing like that, they're a small black cylinder with a tube sticking out in the direction it's supposed to receive from.

These are 16" pedestrian housing. In days past they used to be used as blankout signs (notably by California for "Meter On" signs.) I'm guessing these light up "No Left Turn" and "No Right Turn" when a train is going buy.
Title: Re: What are these?
Post by: Brandon on November 15, 2017, 10:54:32 AM
They look like light up no left/right signs given the railroad tracks next to them.  At this angle, with the train there, they appear to be lit: https://goo.gl/maps/v6ByRFqPNGs  Here's some from Illinois: https://goo.gl/maps/qhK813vctDm
Title: Re: What are these?
Post by: kphoger on November 15, 2017, 01:39:06 PM
Quote from: Brandon on November 15, 2017, 10:54:32 AM
They look like light up no left/right signs given the railroad tracks next to them.  At this angle, with the train there, they appear to be lit: https://goo.gl/maps/v6ByRFqPNGs 

Especially when you enhance the GSV:
(https://i.imgur.com/lqqMT7t.png)
Title: Re: What are these?
Post by: abc2VE on November 18, 2017, 04:37:00 PM
Here's a better shot of one from RVA

https://www.google.com/maps/@37.5734867,-77.483601,3a,15y,324.19h,100.54t/data=!3m7!1e1!3m5!1sw1UrmTh7GRc-_s_xlM4SKQ!2e0!5s20110801T000000!7i13312!8i6656
Title: Re: What are these?
Post by: TheArkansasRoadgeek on November 18, 2017, 05:40:56 PM
Quote from: abc2VE on November 18, 2017, 04:37:00 PM
Here's a better shot of one from RVA

https://www.google.com/maps/@37.5734867,-77.483601,3a,15y,324.19h,100.54t/data=!3m7!1e1!3m5!1sw1UrmTh7GRc-_s_xlM4SKQ!2e0!5s20110801T000000!7i13312!8i6656
Now, I wonder if the one I posted is texted based or symbol based. It could be either...