The U.S. Census Bureau released a report this week on how many Americans bike or walk to work. The strongest "take away" of their news release was that bike commuting is up 60% nationwide in 2012 compared to 2000, and that is the largest increase in commuting mode (including public transit, walking, driving alone, carpooling, and more).
You can read the full report but here's one chunk of the table I find to be most interesting and important:
In Chicago in 2000, 5.7% of workers walked to work, but by 2012, the percent had increased to 6.4%. (I would guess that's a function of the greater number of people living in Streeterville, River North, West Loop, and South Loop who can walk to their central business district jobs.) That may seem like a modest increase, but it's actually bucking the nationwide trend of fewer people walking to work during that time period. Even on the table of the biggest 20 cities above, you can see that only Chicago and San Jose, CA showed increased rates of walk commuting.