英文關鍵字
amber
background
blue
british
building
business
car
center
change
changing
city
clear
color
concept
control
crossroad
direction
drive
forward
green
hanging
junction
light
object
permission
permit
pole
ready
red
road
safe
safety
semaphore
set
sign
signal
sky
start
stop
street
traffic
transport
transportation
urban
waiting
warning
yellow
yes