[OSM-talk] Cycleways and Access tags: Left, Right, Forward, Backward?

[Tobias Knerr]

18.05.2012 12:52 Martin Koppenhoefer:
> 2012/5/17  <rob.j.nickerson at gmail.com>:
>> cycleway:right=* - 9190 occurrences
>> cycleway:left=* - 4329 occurrences
[...]
> maybe oneway-streets do more often have a cycleway only on one side of
> the road, and they are mostly drawn in the direction of traffic flow
> (although -1 is a valid alternative). Given that most of the ways in
> the db are in countries with traffic on the right, but GB is strong
> for mapping cycleways this could explain those numbers.

Yes, this is the most likely explanation. If you look at the taginfo
"combinations" for cycleway:right=*, you will notice that more than half
of these ways are oneway roads:
http://taginfo.openstreetmap.org:8001/keys/cycleway%3Aright#combinations

And almost all oneway roads are drawn accordint to traffic direction,
with the "-1" value at only 1.5%:
http://taginfo.openstreetmap.org:8001/keys/oneway#values

So a large share of the roads with direction-dependent cycleway tags do
actually _not_ have a 50% chance of being drawn either way, because they
are also oneways.

Tobias