While it may be convenient to drive yourself to Disney World, the $14 parking fee will take a chunk out of your wallet. Disney buses are a free, clean and air conditioned alternative. If you are staying on Disney property, the buses conveniently pick up and drop off at your Disney destination (theme parks, hotels, water parks, Downtown Disney area, Boardwalk, etc.). Buses run approximately every 20 minutes.
If you are not staying on Disney property, you can still take advantage of the complimentary bus service by parking for free at the Downtown Disney Market Place or Boardwalk and then catching a Disney bus.
Other free Disney transportation options include boats and the monorail system. If you are staying at the Polynesian, Grand Floridian or the Contemporary resorts then jump on the Resort Monorail for access to the Magic Kingdom. You can also switch monorails at the Transportation and Ticket Center for a quick ride to Epcot.
Fort Wilderness Campground and Resort, the Wilderness Resort, the Grand Floridian, the Contemporary, and the Polynesian resorts offer complimentary boat service to the Magic Kingdom as well.
The Boardwalk offers a boat service and a walking trail to both Hollywood Studios and the back entrance of Epcot. For those who do not know, the back entrance to Epcot allows you to enter the park in the countries, between France and Canada.
At this time, the only way to reach Animal Kingdom is by car or Disney bus.