Baltimore is an old, industrial city with old, car-focused transportation infrastructure. But add a little Zipcar in, and Baltimore residents suddenly get a lot more gung ho about walking, biking, and taking the bus.

Zipcar's only been in Baltimore a year, but according to a survey conducted by the City of Baltimore, its members stopped driving as frequently. Eighteen percent gave up their private cars, and almost three-fourths said they'd be less likely to buy a car going forward. (It probably doesn‘t hurt that Baltimore is not the safest place to live: if your car is a Zipcar, you can worry less about keeping it parked out on the street all night.)