[mkgmap-dev] Road speed through urban areas

Thu Jul 16 00:21:13 BST 2020

Fernando Trebien <fernando.trebien at gmail.com> writes:

> Would mapping boundary=urban [1] help solve the problem of assigning a
> slower estimated speed to ways within dense urban areas in routing
> apps such as mkgmap? [2][3] It looks like an elegant solution to this
> problem that would not have the same issues with verifiability that
> maxspeed:practical has. It is currently common only in France (see an
> example in Rennes [4]) and there is official data available in my area
> that could be imported into OSM. [5]

I don't see why drawing a line that encloses the area where you think
maxspeed:practical is low is any more verifiable.  You are tagging about
an area where people drive slower than the speed limits, I think.  So
it's really the same thing.

Also, maxspeed:practical is easy to verify.  Drive on the road 10 times
and see what the average speed you actually went is.  I have lots  of
commuting data and someday, I will process it and see what the
distributions look like.

If there really are speed limits, then by all means tag them.