apart
blur
branch
caution
concept
control
crossing
crossroad
crossway
crotch
danger
direction
equipment
flash
gravel
industry
infrastructure
intersection
iron
journey
lamp
landscape
light
line
long
metal
off
point
rail
railroad
railway
red
road
roadway
safe
safety
semaphore
sign
signal
sky
sleepers
speed
stop
symbol
track
traffic
transport
transportation
travel
way