Roger a location is in a zoe, usually not just a road.
The basic premis several years ago when CFS started establishing zones on the MFS computer was to have four zones (N,S,E,W) to allow the various resources that surrounded a brigade to be incorporated - no point having the northern neighbouring resource travel to the southen boundary, if there is a brigade there (sounds like several areas in the hills, where the freeway is the boundary lol).
Zoning on the MFS database is a very lengthy task, although once complete is fantastic, at this stage, this state doesn;t have the resources or appropriate system to zone all areas for RCR, Hazmat and alike, hence the geographic locations/suburb use.