[mkgmap-dev] [PATCH v2] Advanced restrictions

Fri May 14 11:17:22 BST 2010

I don't really understand/see the need for the patch yet.

I use --ignore-turn-restrictions when creating any maps currently. You 
can't have one map to have both good autorouting in a motorcar, and on 
bicycle or foot, as we can't encode different road_speed road_priority 
based on vehicle type. As long as there is no answer to different 
road_speed / road_priority I don't think vehicle dependant hardcoded 
turn restrictions help a lot.

What would be much more needed, is a new pedestrian turns restriction, 
and bicycle turn resctriction dataset in OSM, with the default 
assumption that both bicycles and pedestrian can turn everywhere. Once a 
data model for how to encode this in OSM exists (I have not seen any 
yet), the above patch could be useful to generally allow any turn for 
emergency, bicycle and pedestrian, except where specific restrictions 
are given.

Is this patch also able to have dependant on vehicle different avoid 
toll and avoid unpaved road settings? If so then it gets interesting and 
I might find some use for it. On the other hand, turn restrictions in 
general don't bother me much as a cyclist/mtbiker/hiker.

Oh and one more subtle question, are the additional exceptions 
increasing file size? And if so how much? (say disable all turn 
restrictions for pedestrian/emergency - by how much does overall file 
size on country X increase for the default style?)