every interchange should ideally be tagged with the
destination and the
destination:ref keys, the AK Braunschweig-Nord does not have them. Both tags can also be used on primary/secondary/tertiary roads with for example this rule in the style file: highway=primary & destination:ref=* {name '${destination:ref|highway-symbol:box} ${name}' | '${destination:ref|highway-symbol:box}' | '${name}' ; add mkgmap:display_name = '${destination:ref} (${destination})' }
It would be great if you would enrich OSM with both these tags as much as you can, the OSM Garmin maps benefit a lot from it.