Depending on carrier size and loading efficiency, a passenger ropeway can move up to 4000 people per hour, and the fastest lifts achieve operating speeds of up to or . The two-person double chair, which for many years was the workhorse of the ski industry, can move roughly 1200 people per hour at rope speeds of up to . The four person detachable chairlift ("high-speed quad") can transport 2400 people per hour with an average rope speed of . Some bi and tri cable elevated ropeways and reversible tramways achieve much greater operating speeds.