[OSM-talk] maxspeed tagging Was: Best-practice-idea traffic_sign

[Maarten Deen]

Florian Lohoff wrote:
> On Thu, Jul 30, 2009 at 08:44:32AM +0200, marcus.wolschon at googlemail.com
> wrote:
>> In that one case it's okay.
>> Reason:
>> * There can only be ONE maxspeed on a road. ever!
>
> Please add "per direction on a road". Still waiting for a good way to tag
> maxspeed per direction. What we call a "Geschwindkeitstrichter" in German -
> the continues limiting of the maxspeed to a lower value e.g. 100/70/50 up to
> a crossing. This is typically not reflected driving from the crossing where
> only a maxspeed end sign basically is put up.
>
> I also see ofter a limit in the inner lane in a corner but not on
> the outer lane ... This can currently not really be modelled.

Not only in a corner. In Germany the A3, going down the Elzer Berg (near
Limburg an der Lahn in the eastward direction) has a speedlimit of 40 km/h on
the right lane and 100 km/h (or 120? haven't been there in two years) on the
left two lanes.
Speedlimit is imposed because of the steep gradient down and is meant to limit
the risk of runaway HGV's on the right lane.

So the correct wording is: "there can only be one maxspeed per lane per
direction on a road".

Regards,
Maarten