The Traffic Branch was in existence by 1871 when it appeared to operate as a sub-branch of the Engineer-in-Chief. (1) In 1875 the branch consisted of traffic manager; inspectors; station staff, telegraph operators; signal and pointsmen; and porters. Its chief responsibility was the smooth running of the railways, the administration of railway station and service to its clients.
In 1876 the branch reported to the Engineer for Existing lines. It became a separate branch in 1877. (2) In 1884 the branch appears to have been subdivided into the Southern and Western and the Great Northern Railways, although the branch continued to be a single entity. (3) The Interlocking (later the Signals and Interlocking) Branch was established by June 1888 eventually removing the signalmen and pointsmen from the branch.
The branch continued until 1972 when it was succeeded by the Operations Branch (Rail) of the Public Transport Authority in 1972.
(1) Railways oif NSW: report on their construction and working from 1872 to 1875 inclusive. 1876. NRS 15070/1/5 p. 121
(2) NRS 15070/1/6 p. 103
(3) NRS 15070/1/14 p. 187-188