Should you choose not to avail of our car rental Carcassonne Airport service then you may be interested in some information regarding public transport in the area. Transport methods can be quite different in the two main areas of the city (La Cite and the Bastide), one of course being much more modern than the other.
Transport is easier in the newer part of town with reasonable street access and parking however the Cite area as you would expect has much narrower roads. On the plus side, all the main attractions are clearly signposted however its always good to have a map on hand. Parking options can be difficult to find so many people will opt to walk once they get somewhere near where they want to be. Its pedestrian access only in the main area of La Cite.
You can avail of a free bus which runs from one side of the town to the other while there are also local bus options (keep in mind that Sunday is an off day). Head for the tourist office and equip yourself with a timetable or find more information here.
For those with the experience, using a motorbike or scooter may be a decent choice.
Cycling in the city probably requires a reasonable level of fitness as some of those hills can be quite tough. Public transport can be severely limited on weekend.