[Tagging] Roads with no speed limits

Colin Smale colin.smale at xs4all.nl
Sat Sep 3 13:57:50 UTC 2016

That will only work if the road types are mapped correctly to their
official legal status, and not to how they appear. The legal maxspeed on
a road is (unless otherwise signposted) derived from the official status
of a road and should not be subject to "duck tagging". A trunk road may
to all intents and purposes be equivalent to a motorway, yet it is not a
motorway; a tertiary road may be tagged as secondary if it is a bit
wider than usual - yet it would be its official status which determines
the maxspeed, not its appearance. 

As long as we have a subjective element in tagging highway types, it
cannot be relied upon to indicate the maxspeed. So explicit tagging of
maxspeed is actually to be encouraged.

These maxspeeds derived from highway type are perfectly verifiable - by
checking the highway laws of the territory concerned. A motorway in the
UK has a maxspeed of 70mph, and you don't need a speed limit sign to
tell you that. In Europe when you enter a "settlement" (passing a sign
with the name of the settlement) the speed limit (in many countries)
becomes 50kph, and you don't need a sign for that either. 


On 2016-09-03 15:18, Hakuch wrote:

> On 30.08.2016 18:15, Martin Koppenhoefer wrote: 
> sent from a phone
> Il giorno 30 ago 2016, alle ore 12:45, Hakuch <hakuch at posteo.de> ha scritto:
> "Don't map your local legislation, if not bound to objects in reality" 
> default speed limits are bound to physical objects: the freeway, the urban road, etc.

you should read the whole thing on the wikipage as it is very specific
for this problem:

"Things such as local traffic rules should only be mapped through the
objects which represent these rules on the ground, e.g. a traffic sign,
road surface marking. Other rules that can not be seen in some way
should not be mapped, as they are not universally verifiable. " 
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