The Blue Line is a  light rail line running north-south between Long Beach and Downtown Los Angeles, passing through Downtown LA, South Los Angeles, Watts, Willowbrook, Compton, and Long Beach in Los Angeles County; it is one of six lines in the  Metro Rail System. Opened in 1990, it is the oldest and second busiest line in the system with an estimated 28.48 million boardings per year . There are 69 cars in the Blue Line fleet. It is operated by the Los Angeles County Metropolitan Transportation Authority.