accident
asphalt
barrier
black
border
bump
bumpy
car
care
contrast
danger
drop
empty
factor
gray
hump
jump
limiting
line
mark
marker
obstacle
outdoors
parking
pass
paved
policeman
protection
ramp
reduce
restraint
risk
road
roadway
row
rubber
sign
sleeping
speed
stop
street
striped
surface
symbol
traffic
transportation
urban
vehicle
warning
yellow