Buses from Marrakesh run to Ait Ourir about four times a day. Shared taxis (grands taxis) are faster but pack six passengers per car. If you're heading over the Tizi-n-Tichka pass to Ouarzazate, renting a car in Marrakesh and driving yourself is far more comfortable and lets you stop at the pass and the Kasbah Aït Benhaddou along the way.