If it feels like a zillion people are moving to Austin, it is because it is true. A recently published analysis of the rate of migration for the top 40 cities shows that Austin is going at roughly twice the rate of the second fastest city in the U.S. (Tampa). And while Austin is leading the pack, San Antonio is the third fastest growing City, Dallas is #7, and Houston is #12.The rapid population growth of Austin make downtown development important: as thousands of people move to Austin, the City will need to choose between density and sprawl . . .