The CTrain is Calgary's light rail transit (LRT) system, one of the oldest and most successful LRT systems in North America. Operating since 1981, the system has two lines: the Red Line running north-south and the Blue Line running northwest to southeast. The CTrain carries approximately 300,000 passengers daily on a normal business day, making it the busiest LRT system in Canada. The system operates in a downtown free-fare zone (7th Avenue) and connects major destinations including the University of Calgary, Stampede Park, and the airport (via the Green Line when complete). CTrain expansion continues to be a major transportation priority for Calgary.