On 28.04.2013 16:30, WanMil wrote:
My understanding is that routing is also done with the data of lower resolutions, e.g. for long distance routing, but my patch below is probably too simple, as it doesn't care about CoordNode. If that's the case and lower resolutions are used for routing I am quite sure that the merge-lines filter (and some other filters too) are doing harm.
I am pretty sure, that routing is only done at the lowest resolution. This doesn't have to be 24 - (but using mkgmap it actually has to be 24 - Garmin City Navigator uses resolution 23). Maybe confusion is caused by routable basemaps? I would think for them the same principle of routing only using the lowest resolution/level is true. In any case, if the above were true, then there would need to be routing information added too all levels - which I cannot really believe that Garmin would do it...