[OSM-talk] Pedestrian crossings and barriers

Tom Chance tom at acrewoods.net
Sun Jul 29 10:15:35 BST 2007


Hullo,

Peter Miller wrote:
>
> A zebra crossing (white lines on the road to help pedestrians cross)
>
> A pelican/puffin crossing (an automatic signal controlled crossing for 
> pedestrians)
>
> A toucan crossing (a signal controlled crossing for pedestrians and 
> cyclists)
>
> A An underpass for pedestrians
>
> An underpass (for pedestrians and/or cyclists)
>
> A footbridge (for pedestrians and/or cyclists)
>
> A refuge in the middle of the road
>
> A ‘lollipop crossing’
>
> A Pegasus crossing (a signal controlled crossing for pedestrians, 
> cyclists and also horses)
>
Why do we need to know about crossings? Use cases I can think of include:

1 - Maps for pedestrians, cyclists and horse riders with useful 
information like "don't try to cross this road unless your life depends 
upon it", and "here's a safe crossing place"
2 - Routing software for pedestrians, cyclists and horse riders
3 - Routing software generally saying stuff like "turn left 10m after 
the pedestrian crossing"

Well surely all we need to know is that there is some sort of crossing 
over a way, and that certain modes of transport can make use of it? For 
the third instance it might be nice to know the precise kind of 
crossing, but it's not all that necessary. If you're so lost that you 
need to know it's a toucan rather than a pelican crossing I submit that 
you should have read the map better in the first place =)

To my mind we have all the tags we need:

toucan crossing - node with highway=crossing; bicycle=yes
underpass - way with highway=footway; tunnel=yes; layer=-1

And so on. It's international, requires no extra tags, and gets the most 
important info out. If people then want to add country-specific 
identifications like crossing=toucan or whatever then that's great. One 
question to resolve is the difference between traffic_signals and 
crossing, since I've been using the former for pelican crossings and the 
latter for zebra crossings.

> It may be appropriate to make the assumption that on primary, trunk 
> and motorways that crossing is not possible (unless tagged to the 
> contrary), and the for all other road classes it is (unless there is 
> tagging to the contrary).
>
That sounds sensible, and on secondary and tertiary roads we might 
assume that one should look for a crossing point rather than running out 
into the road, whereas with residential and unclassified roads you could 
probably safely cross anywhere - just look left, right, left kids!

Kind regards,
Tom




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