[Tagging] "width" on streets: Time for a recommendation
voschix at gmail.com
Tue Sep 15 08:51:27 UTC 2020
On Tue, 15 Sep 2020 at 10:34, Tobias Zwick <osm at westnordost.de> wrote:
> I plan to soon implement a "What is the width of this road" quest in
> StreetComplete where the user can measure the width of the road using his
> or her smartphone (similar to the app Measure from Google ). The app
> will need to instruct the user very clearly what should be measured.
With the satellite photos that OSM can legally use, we usually have a
resolution problem. In most cases it will be tricky to get to a precision
better than one metre, which in my view is not enough.
Alternative: use est_width= or width= plus source.width=estimated
Another problem are the contrast enhancement filters that most satellite
images are subject to. They oftenwiden the roads to some extent or create
an artificial limiting line, depending on the filtering algorithm.
In case there are Mapillary Mapillary photos you can, in many countries,
count the stripes of zebra crossings (in Italy they are 0.5m wide) to
measure the width of urban roads.
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