There are a few obvious transportation ideas that I'd implement:
-Downtown would be outfitted with a comprehensive Rapid Bus system that would include, but not be limited to, signal priority, bus lanes, etc. and not stop every block or two (vis a vis current Capital Metro on Congress). This system would run very often (10min maximum wait) during peak times (which can include typical rush hours, special events, and weekend nights.)
-Turn current Amtrak station into very large downtown transit center and give pedestrian access to Whole Foods, town lake pedestrian bridge, Spring condos, etc. Downtown Transit Center would include RapidBus transfers and routes such as:
-Erwin Center by way of Red River, serving both the RR district and Brackenridge.
-DKR Texas Memorial Stadium, connecting with campus bus transfer points
-Convention Center by way of 4th St, serving the Warehouse District
-the Capitol, serving the government buildings
-Sink MoPac (similar to Central Express/US-75 in Dallas) between Town Lake and Northland/2222 and toll it from between Capital of TX Hwy south and 183 North. Add one, non-tolled HOV lane each way.** Keep and acquire the Union Pacific tracks on the surface.
-Somehow retrofit the UP tracks from downtown both directions (north and south) to allow for electric rail cars.
-Allow for easy pedestrian access to Domain Rail Station.
-Acquire the state buildings across MoPac from Camp Mabry; zone them for ultra-high density (no more than 30-stories) residential and give pedestrian access to nearby electric rail station on MoPac.
-Acquire land bordering UP tracks south of downtown; demolish homes and zone for higher density. Build 2-3 satellite park and rides.
-Not sure about the east-west tracks in South Austin - they run under I-35 @ Ben White - but include a rail service to ABIA. Service would run often (10 minutes) during peak hours. Rail would allow access to park and rides and downtown transit center.
-Build a tunneled, east-west expressway under 35th street from I-35 to MoPac.
-Lamar Blvd tunnel from 1st St to 9th/10th St. to allow for a more pedestrian-friendly environment around Whole Foods, Waterloo, etc.
-Add an additional general-use lane on 183 between MoPac and McNeil/Spicewood Springs Rd.
** - I decided to toll MoPac for a couple of reasons: 1) it would be a huge moneymaker and, 2) I want to punish those opting to drive when there are other alternatives, as opposed to now where drivers are punished for driving yet are present with no other reasonable alternatives.
I'll come up with something for I-35 later.... it hurts my head too much.