checkpoint
3d
barricade
barrier
border
boundary
building
car
cartoon
check
closed
construction
crossing
danger
design
entrance
entry
fence
forbidden
gate
guard
highway
hurdle
icon
illustration
industrial
industry
isometric
maintenance
object
obstacle
parking
patience
protection
railroad
restricted
road
roadblock
roadsign
safety
security
sign
stop
street
striped
traffic
transport
warning