 On working days, two services operate every hour (20 or 40 minutes apart) and together with an hourly service on line S19, services operate at 20-minute intervals.Between the peaks the S12, S13 and S19 services provide a service every 10 minutes on the central section between Köln-Ehrenfeld and Köln-Trimbornstraße.It operates every 60 minutes on Saturdays, Sundays and public holidays between Düren and Troisdorf; lines S13 and S19 jointly provide a service every 30 minutes.