I find it amusing that he opened with the A28 because that’s about the only proper route number I can remember paying attention to - it’s useful for running the non-toll route north/south through Sydney. Even then though I would refer to that particular road as the Cumberland highway, the route number is just for keeping track when changing to a differently named road (which you do a few times going through that way).

Generally speaking the only roads I remember by number are a few Sydney motorways that don’t have prominent names - what comes to mind is the M5/7/8 and I guess the M4 (though that’s partly the F4 in my memory due to spending some early childhood in the Blue Mountains before moving elsewhere).

First time seeing the Ring Roads shield… I can’t really think of any ring roads in Sydney but I might be wrong

TL;DR because the numbers are a mess and keep changing.

I stopped counting after the M1. I don’t even know what the M2 is.

Edit: I looked up the M2 and realised I went there once to do work on the Lane Cove Tunnel.