If anyone has read any of the highway blogs on the O'ahu thread they probably have noticed the 1946 Army Day Map from Oscar's page that I reference regarding World War II era Military and Hawaii Routes:
http://hawaiihighways.com/1946-army-day-map.pdf
The Military Routes are US Route Shields whereas the Hawaii Routes are Spades I believe were likely supplied by the California Auto Clubs. I had some observations based off looking at the Army Day Map:
- Military Routes 1, 2 and 3 clearly are the most important highways. They seem to function very similar to how Interstates H-1, H-2 and H-3 do today as being primary transportation corridors on O'ahu.
- Military Routes 11, 12, 13, 16 and 17 are functionally the Secondary Tier of Primary Highways (example; Military Route 16 is aligned over the Old Pali Highway). All the two digit Military Route connect to Military Route 1 (which circles O'ahu). There is no Military Route 14 or 15 for reasons I can't discern.
- Some of the one and two digit Military Routes have spurs like Hawaii Route 12A.
- The Hawaii Routes for the most part are in the 1XX, 2XX or 3XX ranges. Overwhelmingly most connect to Military Routes 1-3 with some exceptions for the two digit Military Routes. For the most part the number assignments seem to be sequential and/or clustered similar to hybrid or Washington and Nevada State Highway Numbering assignments.
I don't know, this seems like a really sound numbering system to me and well thought out. I get that the 1955 System is based off Federal Aid Program assignments based in numbering ranges. At first blush that's a pretty decent system too until you get into overly recycled numbers and weird shit like 76 becoming 760 only to be reverted back to 76 later.