sister showed me this
@elilla Hey, red, yellow and green are used with the same meanings in railway signalling too!
@zuthal @elilla Ooh, incorporating some of the fancier railway signal aspects might be useful!

green: continue
green blinking: continue, limiting speed
yellow: slow down, be prepared to stop
yellow blinking: navigate on sight, be prepared to stop
red: stop
@that @zuthal @elilla
blue: shunting operations not allowed
white: shunting allowed
@chfour @that @elilla somehow need to incorporate a DO NOT HUMP stencil into this
@chfour @that @elilla presumably as a tramp stamp for someone who exclusively tops