The CTA operates a bus system and a rapid transit system, known as the "L," in Chicago. The L Train runs on eight routes, designated as Yellow, Red, Brown, Blue, Green, Pink, Purple and Orange. The Blue line has a stop at the O'Hare International Airport, while the Orange line stops at Midway International. Chicago is one of few cities with 24-hour transport service, as the Red and Blue lines both run all day.