In 1946 a Commission of Enquiry into the Electrification of the Brisbane Suburban Railway System was held and its 1947 report recommended the installation of a similar electric rail system to Sydney and Melbourne. It was argued that electrification would provide a faster, cleaner service and would eventually lead to the settlement of the outer suburbs. In February 1949 approval was given to electrify the Brisbane suburban railway system at an estimated cost . Planning began in February 1950. The project included an upgrade of stations, platforms, the signalling system between Corinda and Northgate and the provision of subways at some stations. Subways were installed to avoid overhead bridges in the vicinity of power lines. The quadruplication of the line from Corinda to Virginia was necessary, with or without the electrification process, because both incorporated important freight lines; Virginia on the main northern line and Corinda on the main western line. The survey between Virginia and Corinda was completed by June 1950. The quadruplication was later extended to Zillmere.