alert
barricade
barrier
black
block
boundary
caution
city
closed
cloudy
color
construction
danger
daytime
dead
direction
driving
end
gate
horizontal
improvement
isolated
metal
nobody
obstacle
orange
overcast
red
repair
road
roadblock
rural
safety
sign
signage
signal
site
stop
street
striped
stripes
symbol
text
traffic
transportation
warning
white
work
workers
yellow