barrier
beware
caution
command
crossing
danger
direction
engine
flat
geometric
illustration
locomotive
logo
moving
notice
object
pattern
public
railroad
railtrack
railway
repeat
repeating
road
roadside
roadsign
safety
seamless
sign
signage
signal
signpost
steam
stop
symbol
technology
texture
track
traffic
train
transport
triangle
wait
wallpaper
warning
way