For the last century or so, cities have been struggling with the paradox of parking: Cars need large amounts of space, but making room for them comes at a direct cost to the vibrancy that makes the people in the cars want to come in the first place. Brian Canepa and Joshua Karlin-Resnick lay out the cost of parking requirements and the potential benefits of reducing or eliminating them in this May 2015 Planning magazine article. They focus on three cities that have done so: Sacramento; Columbus, IN; and Ann Arbor, MI.