The CTrain began operations in 1981 with the South Line (now part of the Red Line). The system was built as part of Calgary's preparation for the 1988 Winter Olympics and has since expanded to become one of North America's most successful light rail systems. Notable for being one of the first systems in North America to be fully powered by renewable energy, the CTrain carries over 300,000 passengers on a typical weekday. The system features a free fare zone in downtown Calgary and has been instrumental in promoting transit-oriented development throughout the city.