advance
alert
attention
brake
caution
country
daylight
direction
distance
drive
forward
generating
give
highway
hills
icon
information
instructions
intersection
interstate
lane
law
merge
message
notice
outdoors
outside
pole
red
regulation
rest
road
roadside
roadsign
rule
rural
safety
sign
signage
signal
stop
street
symbol
traffic
transportation
triangle
warning
way
white
yield