[mkgmap-dev] Short Arc Problem? Error 3 Mapsource, Problem on Calculating this route Basecamp.

Thu Jan 3 19:17:07 GMT 2013

Maybe it helps if I explain what happens in detail with the mp:

1. The mp calculates the tags for the mp. In this case the tags of the 
mp are used which are [area=yes; highway=residential]
2. These mp tags are removed from all outer ways if they are identical. 
In this case no tag is removed from way 114405617.
3. All outer ways are copied and tagged with the mp tags. These copied 
ways are only processed by the line style file. They can be identified 
by the additional tag mkgmap:mp_created=true.
4. All outer polygons are tagged with the mp tags and are processed by 
the polygon style file only. They can also be identified by the 
additional tag mkgmap:mp_created=true.

Point 2 and 3 are required because in OSM the mp *and* the outer ways 
are tagged quite often.

In this case it creates a residential way (point 3) with identical 
coords like the tertiary way 114405617.

WanMil

> But that change causes problems for other parts. There are some
> highway=residential areas without ways that cross them, so in order to
> have routing work in some inner city cases, you must make sure that you
> route along the edges.
>
> If multipolygons were treated the same way as relations, that would make
> it easier to make sure only one routable highway gets created (because
> add highway onto highway would not add the highway, because there is
> already an underlying highway).
>
>
> The only thing I could think that does cause problems, if two routable
> lines are on top of each other, and both have the same road_type and
> same road_speed. Maybe there could be a check in the mkgmap continue
> function, never to create two routable lines on top of each other, if
> both road_speed and road_type are identical.
> On 03.01.2013 14:44, Minko wrote:
>>
>> The issue also disappears when you use
>> highway=residential & area!=yes [0x06 road_class=0 road_speed=2 resolution 22]
>> instead of the default rule
>> highway=residential [0x06 road_class=0 road_speed=2 resolution 22]
>>
>> So it got to do with those two routable lines on top of each other
>>
>>
>