英文關鍵字
allow
blue
car
change
city
cloud
color
concept
control
cross
crossroad
danger
day
drive
environment
equipment
green
information
intersection
junction
light
nobody
object
ready
red
road
safe
safety
semaphore
set
sign
signal
sky
space
stop
stoplight
street
symbol
traffic
transport
transportation
travel
urban
walk
warning
way
yellow
yes