[mkgmap-dev] Routing Problem in Southern Minnesota

Tue Dec 22 22:36:44 GMT 2009

Hi Jeff,

> I'm having an issue with routing in southern Minnesota along I-35 with
> my Oregon 300 (firmware 3.40).  If I pick two points along I-35, one
> south of Albert Lea and the other north of Owatonna my Garmin wants to
> route me over to US 218 instead of using I-35.  The same route using
> Cloudmade just goes straight up I-35 as one would expect.  Is this a
> bug in my Garmin, is there a deficiency in the OSM data or am I
> generating my maps incorrectly?   I'm using osmosis merge last week's
> planet plus the dailies and then split out Iowa and Minnesota.  I've
> attached a PNG which shows the odd route the Garmin gives me.  I've
> used JOSM to look over the data in OSM and fixed the obvious issues.
> Can anyone point out where I'm going wrong?

I have just downloaded that area (with josm), made a map with the
current mkgmap and tested the routing on I-35 using mapsource. It can
route from the bottom of I-35 to the top without diverting off as shown
in your picture. So perhaps the data you have is broken?

Cheers,

Mark