alert
attention
barrier
beware
border
boundary
caution
city
cone
construction
danger
development
direction
driving
equipment
forbidden
highway
hurdle
indication
industrial
industry
maintenance
marking
object
obstacle
orange
pass
plastic
prohibition
road
roadside
roadway
roadwork
safety
security
sign
signal
speed
stop
street
striped
symbol
tool
traffic
transport
transportation
triangle
urban
warning
works