abstract
ahead
alarm
alert
attention
background
ban
black
car
caution
communication
congestion
crowded
danger
design
forbid
forbidden
graphic
hazard
icon
illustration
indication
information
isolated
jam
mark
no
notice
patience
pictogram
prohibited
protest
public
red
repeat
restrict
risk
road
safety
sign
stop
symbol
traffic
transport
transportation
travel
warning
zone