No public transportation means no public transportation that smells like urine. Since housing is so cheap everyone has nice cars.
Anecdotal example: when we lived in Tel Aviv (bad transit, although probably not as bad as many places in the US) I had several jobs and it would take me 50-60 minutes to get from home to work or vice versa.
This was not just me but is usual in greater Tel Aviv, unless you can afford to live in the city (almost nobody with kids does, metro tel aviv has 3.7m residents vs 450k for the city itself).
We've lived in Vienna before we moved and moved to Berlin after, both cities with great transit (that sometimes smell like piss). Both metros are comparable in size to TLV (metro Vienna 2.6m, metro Berlin 4.5m) and I've had several jobs in either - it usually takes 30-40 minutes to get to work and again it's not just me but the common case.
The problem is there is a culture of driving in Austin and not of taking the public options. Most people don't even know what is out there. We could do with quite a few less cars on the road.
Thankfully the climate is outstanding so I don't even need A/C.