The Southern Sydney Freight Line (SSFL) is a freight only railway line in the south-western suburbs of Sydney, Australia. The line was constructed to avoid a curfew for freight trains that restricts them from operating in the suburban area during peak hours.The SSFL forms part of a dedicated freight only corridor between Macarthur and Port Botany. The line is managed by the Australian Rail Track Corporation (ARTC), while the adjacent passenger lines are managed by RailCorp.