Good back roads S.A. to Austin?

I drive from Austin to SA at least once a month and I take HWY 290 south to 165. 165 ends at loop 163 in Blanco, which connects to 281. 281 goes all the way down to SA. It's a nice scenic route. 1000 times better than taking I35.

So from SA to Austin... US 281> Loop 163> FM-165> HWY 290

 

...it's not really a driving road per se, but as mike says, 281 to 290 is far nicer than interstate 35...there are some really fantastic proper driver's roads out west of san antonio and austin both, so if they'd like to take the very scenic route (and tack perhaps three hundred extra miles onto their trip) i can recommend some quite roundabout circuits where it's far more about the drive than the destination...

 

Yes! On the west side of town there are two roads you need to take if you're just going to go for a drive. RM 2222 and City Park Rd. 2222 is a wonderful curvy road with lots of hills that rise and fall as they turn. Only problem with that road is the traffic, it's not too much, just dangerous if you want to go really fast. Anyway, take 2222 west from Austin a bit and then turn left onto City Park Rd. less than a mile past loop 360. City Park rd pretty much has no traffic what so ever because it just goes down to the water and that's it. It's a long twisty road with beautiful scenery. Those are my two favorite roads so far.
http://maps.google.com/maps?f=d&source=s_d&saddr=Northland+Dr%2FRanch+Rd+2222%2FRM-2222&daddr=City+Park+Rd&hl=en&geocode=FVznzgEdyFws-g%3BFfTLzgEdOwor-g&mra=ls&sll=30.33851,-97.810421&sspn=0.108448,0.154495&ie=UTF8&ll=30.343769,-97.800636&spn=0.054221,0.109863&z=14

 

Don't forget about Lime Creek Rd.