alert
attention
beware
black
building
caution
collection
construction
danger
digging
highway
icon
isolated
metal
metallic
object
obstacle
progress
repair
restriction
road
roadside
roadsign
roadway
roadwork
safety
set
sign
signpost
simple
site
speed
stop
street
symbol
traffic
transport
transportation
triangle
under
warn
warning
way
white
work
worker
yield