I have seen a proposal for a low cost type of warning device for grade crossings that do not have fully automatic electric gates and lights. It uses the locomotive headlight to illuminate a warning sign. The headlight shines onto the device; the light is received and turned 90 degrees to pass out in line with the direction of the roadway. As the light exits the device, it passes through a stencil with the word, “YIELD.” Apparently there is some optics inside of the device that concentrates and focuses the incoming locomotive light as well as turning it 90 degrees.
Has anyone seen the application of this type of device or similar non-electrified devices?
The state of Ohio has a similar crossbuck set up. There is a setup below the croosbuck that is supposed to reflect the light towards traffic on the road. They are used at rural and light road traffic crossings. The light doesn’t reflect through a yield sign but there is yield spelled out in reflective material. I’ll see if I can find a picture of one.
Edit- Here a link with a few pictures of them, http://www.geocities.com/ryanstrafficstuff/railroadcrossings.html
Didn’t the small electric underground trains of Chicago use a similar setup?
From what I recall, they put green jewels or reflectors at intersections of two different raillines, and an approaching train’s light would illuminate this reflector, giving warning to any trains on the intersecting track.