CTrain is a light rail transit system in Calgary, Alberta, Canada. It began operation on 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. As of 2017, it is one of the busiest light rail transit systems in North America, with 306,900 weekday riders, and has been growing steadily in recent years. About 45% of workers in downtown Calgary take the CTrain to work.