Why light rail is a fail:
Today I took the train to downtown Austin. Mostly, I just wanted to try it out and see how the logistics worked out, and I had a meeting downtown that was an excuse to try it.
It took 1.5 hours, each way. In light traffic, the drive is 20 minutes. In heavy traffic, it would be more like 45 minutes.
Included in that 1.5 hours is 11 minutes of driving just to get to the station (there are three stations within a 11-minute drive, the most convenient of which has essentially zero parking). The train ride is 40 minutes, the wait for the next train is 30 minutes, and the walk between the car parking and the train is about 10 minutes (huge parking lot). So I saved about 20-60 minutes of driving (still driving a total of 20 minutes, remember), and in exchange I spent 3 hours commuting instead of .75 - 1.5 hours of commuting.
The bus would take about 50 - 70 minutes.