[mkgmap-dev] Inter-tile routing now available in trunk

Sat Feb 28 13:30:34 GMT 2009

Johann Gail wrote:
> 
> 
> 
>>> I've tried now with r942 on a etrex and seen the following:
>>>
>>> Crossing S/N borders seems to be no problem, routing gives more or less
>>> reasonable routes.
>>>
>>> Crossing E/W borders doesn't work ok, as described by others too. In my
>>> case it alway finds a route, but the route is really not optimal. The
>>> inter tile crossing always takes place at a highway or a secondary one,
>>> even if start and destination are only a few kilometers appart and far
>>> from a highway.
>>>
>>> My impression is, that routing on E/W borders doesn't work at all, but
>>> takes place at the basemap instead.
>>>     
>>
>> I've removed the basemap from my 605 and have the same East/West
>> problems so I can't see how it can be doing that. As I've already
>> commented what I saw was that when routing east I would be directed
>> along primary roads until I'd crossed the tile boundary (I didn't
>> measure this exactly but it was close) and then directly to the motorway
>> after which the given route was what I would have chosen myself
>>   
> So you have the same effect, that routing over borders takes always
> highways, even without a basemap on the device.
> 
>>> I've verified with two different start/destination pairs. Crossing
>>> borders in E/W takes only place, if roads in the basemap are available.
>>>
>>>     
> Ok, the difference may then be only the road type primary one. As all
> primarys are in the basemap too, it is hard to distinguish.
>>
>> I don't know what else to say really. I know this is a work in progress
>> and am happy with results so far. Inter-tile routing was never going to
>> be easy
>>   
> I think it is only a small detail missing, as routing in S/N direction
> works fine already.
> _______________________________________________

It's time to eat humble pie. I managed to create a single tile with all
the places and roads on that I've been testing and this chooses exactly
the same route as the inter-tile file. It seems it was just a
coincidence that the routes hit the motorway around the tile boundary.

I'm currently experimenting with different options for motorway speed
and primary road class and speed as the routes being selected are (for
me anyway) far from optimal

Apologies for the misleading info

Cheers

Paul