> Address index is in the bike layer, and is searchable even if
 > the layer is not active.

Obvious configuration would be to put search index in non-routable map. 
There is some problem in mkgmap, which doesn't create index without 
routing. I think index could be available if option --net is used, but 
this didn't work for me.

My solution is to create full routable map and send it from Mapsource to 
GPS without routing information.