Directional Sign for Tunnels

[Hirnsausen]

A very basic sign, meant to be used in underground tunnels, that can be placed directly on rock or soil walls, without requiring any static core. Those signs feature only an arrow and come in eight variations. pointing to the left, right, up, down, and the four diagonal options in between. basic element, no own illumination, needs astronaut's light to be fully visible, but reflects light well (like street signs). Colors would be blue for the background and white for the arrow. An option sign would be a "No Go" or "Don't pass" sign, round, similar to a today's "No Parking" sign.

Those directional signs will greatly improve the usage of complicated tunnel systems without turning into wrong tunnels.