Airways in Australia

[Hawker114]

Is there any reason or significance to the assignment of letters to airways in Australia. The USA seems to have some logic, with J for airways >FL180 and V<FL180. Yet Australia seems to use just about every letter in the alphabet?

[MakeItHappenCaptain]

AIP GEN 3.2

2. AIR ROUTE DETAILS, SPECIFICATIONS AND CHART DEPICTIONS
2.1 Air Routes
2.1.1 Air routes consist of ATS conventional and Area Navigation
routes.
2.1.2 The following designators are used to identify ATS conventional and Area Navigation routes:
a. Conventional Routes:
Regional routes A, B, G and R.
Domestic routes H (one way) & J (two way). Domestic routes V (one way) & W (two way) - predominantly low-level.
b. Area Navigation Routes:
Regional routes (Tasman) L, M & N.
Domestic routes Q (180_ - 359_), Y (360_ - 179_),
T (two way) & Z (low level).

And actually, in the US, V is a VOR or VORTAC defined route, J is a jet route on Enroute High charts, again, VOR or VORTAC defined, T & Q routes are Enroute Low & High RNAV routes, but yes, Australia does have a couple more and you still have to look up their names for a flight plan, so what's the difference? Australia just gives you more information, ie. one or two way routes.
Some US states also have four types of coloured airways on L/MF (NDB) defined routes, depending if they're N/S or E/W. Not so simple now.