The Dakar Rally or simply "The Dakar", formerly known as the Paris–Dakar Rally, is an annual rally organised by the Amaury Sport Organisation (ASO). It is a rally raid, an off-road endurance race, traversing terrains notably more demanding than prepared roads used in traditional stage rally competitions, and the vehicles used are purposefully built to perform off-road: cars, trucks, quads and motorcycles intentionally designed to endure cross‑country journeys on unpaved terrain. Most timed competitive segments, known as 'special stages', consist of crossing dunes, mud, camel grass, rocks, and erg. Individual stages range in length from several dozen kilometres to as much as 800–900 kilometres (500–560 mi) per day. Hallmarks of the Dakar Rally are the physical and cognitive demands of prolonged driving, navigation and environmental stressors that the competitors are subjected to. Insufficient experience with desert navigation, mechanical troubleshooting or endurance racing techniques, combined with the fatigue and the rough terrain, often result in accidents and serious injuries.