Because the line was built to normal railway standards and not to subway standards, only specially-designed trains can travel along the Keio New Line. However, since new train cars are being designed to be able to operate on above-ground and below-ground tracks there is no real issue with the differentiation. All trains operating west of Sasazuka Station start and arrive at Shinjuku Station. During events at the Tokyo Racecourse, there are express trains that operate from Fuchūkeibaseimonmae Station to Shinjuku station.