[OSM-talk] Turn left restriction on two way highways

Hendrik Oesterlin hendrikmail2002 at yahoo.de
Fri Dec 31 08:26:00 GMT 2010

"Eugene Alvin Villar" seav80 at gmail.com wrote on 31/12/2010 at 18:51:05 +1100
subject "[OSM-talk] Turn left restriction on two way highways" :

>>> I remember a suggestion like this a long time ago. Tagging a way with
>>> restriction=no_left_turn (especially if it has a oneway=yes tag) would
>>> specify a default for that particular way only. This is much easier
>>> for routers or preprocessors to adopt.
>> But today it is not supported by any routing engine I know of.
>> Even the Garmin file format created by the mkgmap tool cant't handle
>> this today.

> Not currently, but preprocessors such as mkgmap can adopt this. Garmin
> routers themselves have *no* conception of turn restriction relations
> as they exist in OSM--it is mkgmap that translates these turn
> restrictions into the format that Garmin understands. So it should be
> just an additional code in mkgmap to support restriction=no_left_turn
> tags on ways.

This is correct. We should ask on mkgmap-dev at lists.mkgmap.org.uk  if
the implementation of this kind of tagging would be easily possible.

Who is making the eMail? Should I do it (available again only in 2 days)?

Hendrik Oesterlin - email hendrikmail2002 at yahoo.de

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