Add that to the amount of residences already built/being built and the amount of offices already built/being built downtown and you have some pretty intense density/foot traffic. Gotta give kudos to the city council for being forward-thinking and implementing the Great Streets program when they did. As inconvenient as it can be, it's only a little bit at a time and it will pay off in the long run.
Here's an article talking about it all the way back in 2002:
http://www.austinchronicle.com/news/2002-10-04/104053/