Almost certainly freeways ... will become "stranded assets" well before the end of their economic life in 60 years' time.

Not at all! They will become really sweet bikepaths as soon as we get the oilburners out of the way.

Even if my dreams of a fully electric car fleet don't eventuate, the freeways will be useful for buses or for laying down light rail tracks.

Maybe the outer lanes could be used for bikes, but personally I prefer my bike path to be well away from cars (and I've got to say the one I ride down to North Sydney is great in that respect).