Sydney Trains is the operator of the suburban passenger rail network serving the city of Sydney, New South Wales, Australia. The network is a hybrid urban-suburban rail system with a central underground core that covers over 813 km (505 mi) of track and 170 stations over eight lines. It has metro-equivalent train frequencies of every three minutes or better in the underground core, 5–10 minutes off-peak at most inner-city and major stations and 15 minutes off-peak at most minor stations. During the weekday peak, train services are more frequent, while frequency decreases on weekends and off-peak.