You have plenty of options for getting around in Philadelphia [1], between public transportation, taxis, and the easy-to-navigate, grid-like streets that are great for walking and biking. There is rarely a reason to drive your car in Center City when you factor in the difficulty of parking in the busiest parts of town. It’s usually best to ditch the keys unless you’re traveling outside of Center City, where limited public transit and ample parking make driving convenient.
Links:
[1] http://www.moon.com/destinations/philadelphia/discover-philadelphia