art
black
color
crossing
danger
design
element
flat
icon
illustration
isolated
level
light
line
locomotive
metal
object
old
outdoor
outline
pointer
priority
rail
railroad
railway
rhomb
road
safety
shape
sign
signal
silhouette
single
special
station
steam
stop
symbol
technology
thin
traffic
train
transport
travel
vertical
warning
way
web
white