When parking your vehicle near someone else's driveway you must park at least 5 feet away from each end of a constructed driveway.
If someone parks closer than 5 feet near your driveway or parks in front of your driveway you can call code enforcement and have them ticketed.
Or you can dial the police non emergency number and report the car being parked too close to your driveway and they can have the car or other vehicle towed.
If possible put a note on the car and ask them nicely to not park there that close and let them know they are blocking your driveway.
If that fails or you don't want to do that then just contact police or code enforcement and they can usually get the vehicle to be moved or move it themselves.