By air, the airport is a few kilometres from the centre and handles seasonal low-cost routes from several UK and northern European cities. It is small enough that you are outside within fifteen minutes of landing. Toulouse is the larger alternative, about an hour away by road or rail, with year-round connections.
By rail, the station sits at the northern edge of the Bastide, a flat walk of about ten minutes to the apartment. Trains run along the Toulouse to Narbonne line frequently, and Narbonne connects onward to Montpellier and the coast.
By road, the A61 passes just north of the town. It is a toll road and the exit is well signed. If you are coming from Spain the drive over is straightforward, and from the north it is the long haul down the A75 through the Massif Central, which is spectacular and slower than the map suggests.
Parking is the one genuine friction. The Bastide is a grid of narrow one-way streets with resident permits on most of them. There is paid parking within a few minutes' walk and free parking further out towards the river, and the practical answer is to unload first and park afterwards rather than circling with a full car.
If you are not planning day trips, consider not hiring a car at all. Everything in Carcassonne itself is walkable, the train reaches the coast, and a car in the Bastide is more of a liability than an asset.
