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