What is "ctrain"

CTrain is a light rail transit system in Calgary, Alberta, Canada. It began operation in May 25, 1981 and has expanded as the city has increased in population. The system is operated by Calgary Transit, as part of the Calgary municipal government's transportation department. It is now one of the busiest light rail transit systems in North America, with over 300,000 daily riders, and has been growing steadily in recent years. About 45% of workers in downtown Calgary take the CTrain to work.