I'm given to understand that, at one time, Austin was also a "sleepy college town". They got excited about growth in the early 80's when Texas Instruments set up shop. They started development, and were left holding the bag when TI split shortly thereafter.
When I got there in 1990, they were growing again. It seems the TI fiasco left such a bad memory that they were determined to delay expansion of public utilities - fearing another collapse. That clearly didn't happen. They ended up about 15 years behind where they should have been.
Additionally, I'm given to understand that sometime in the 70's, the power-brokers had decisions to make on whether or not Austin should remain a sleepy little city or expand to something more like Houston. They decided to remain small, and one way they did that was by choking infrastructure (not approving road expansions, etc.), figuring that cities that can't accommodate more hustle and bustle won't get it. Generally, history was on their side.
Then Michael Dell plopped offices up in Round Rock and blew up the north end of the city. Samsung set up shop on the east side of town, changing that area also. By the time I arrived in 2004, the city proper had, I want to say, 500kish people, all trying to get around on roads built to serve a few hundred thousand less than that. This was explained to me by a disgraced lawyer who had once been a highfalutin wingman to People Who Matter. Or so people told me.
Now Elon Musk has plopped Tesla out by the airport, but even before that, as far back was 2010-2011 I was reading that hundreds of people were moving to Austin every day and the population was growing at a crazy rate.
The toll roads have undoubtedly helped, but nevertheless traffic seems worse than ever when I'm there.