The parking rhetoric in Ann Arbor is that a structure is full if it's at 85% capacity, based on one consultant's recommendations. I'd like to challenge that and say that no one really cares how full a garage is if you know that you won't be frustrated finding a space.
Statistics show that 10% to 15% of the parking spaces in garages are not used, even when the garage appears full. In a parking structure such as Century City with 2,500 spaces, that means that at any given time, the garage could “appear” full, but it would have 200 to 400 spaces available. “You just couldn’t find them, at least not easily,” deWildt says. “It’s like we had built a 400-space garage.”