If Brisbane's old tram network was still operational, it would be the third-largest today. That's without any further investment compared to where it was at in the 1960s.
We had a train line—or at least a tram line—running right down the Gympie/Lutwyche/Bowen Bridge Rds corridor into the CBD and across to South Bank. We could definitely have that again. Or alternatively (or even better, in addition to that), light rail running east-west connecting from the Northwest Transport Corridor (which would be built out as a heavy rail line) to the existing Caboolture/Nambour Line, via Gympie Rd.
But yeah, the existing Gympie Stroad is just awful for the city. It's an incredibly inhospitable place if you're outside of a car, and it's not exactly a nice place to drive either.