attention
blue
car
caution
cloud
communication
control
danger
direction
drive
forbidden
green
halt
highway
information
isolated
landscape
low
meadow
metal
net
nobody
object
octagon
pole
post
prairie
road
roadside
safety
sign
signage
signal
single
sky
speed
stop
street
symbol
text
traffic
transport
transportation
travel
warning
way
white
word