Some more info, just checked it with mkgmap version 2570 which seems ok, so it must be in the later revisions, I think routable_types_v6.patch is the cause (2573)?
I have tested it with two line types: highway=trunk [0x02 resolution 18] road is removed
highway=trunk [0x02 road_class=4 road_speed=5 resolution 18] road is rendered
It doesn't matter if I use a non routable line type for 0x02, or convert it into motorway. Any ideas what makes this road disappear?
BTW I need to make motorways, trunk roads and all other non cyclable roads not routable, because access=no / bicycle=no is not working anymore in the latest devices and Basecamp. But I do want to see them rendered at the map and sometimes I see those holes.
I have uploaded the map tile here: http://mijndev.openstreetmap.nl/~ligfietser/test/10010069.o5m