accident
alert
attention
barrier
black
block
border
boundary
build
caution
construction
danger
direction
equipment
forbid
hazard
highway
icon
isolated
marker
measure
obstacle
orange
precaution
prevent
prevention
protect
protection
protective
regulation
repair
road
safe
safeguard
safety
security
sign
stop
street
stripe
symbol
traffic
transport
transportation
two
warn
warning
white
work
yellow