Carcassonne is walkable end to end. The Bastide is a flat grid; the Cité, on a hill, is a fifteen-minute walk up from the river. Cars are not allowed inside the Cité walls and the parking outside is congested in summer — leave the car at one of the signed lots and walk in.
A free shuttle (the "Navette de la Cité") connects the railway station and the lower town with the Cité, running every fifteen minutes in summer. Bicycles can be rented at several points along the Canal du Midi.