introduction of power signalling on the line begun in 1919 with the section from Richmond to East Richmond, with the remainder of the line converted in stages from 1922 to 1964. In 1929, the Glen Waverley line began construction on an extension from Darling to East Malvern along the original track of the Outer Circle line. The Outer Circle line previously begun its curve south towards Waverley Road and Oakleigh. The Glen Waverley line continued east towards Holmesglen. The 1950s saw the line undergo major upgrades, including the first centralised traffic control installation in Australia. Commissioned in September 1957 at a length in length, the Victorian Railways installed it as a prototype for the North East standard project. On 6 February 1956, the Toorak Road level crossing, between Kooyong and Tooronga stations, was the first in Victoria to receive boom barriers, replacing hand operated gates. New Comeng trains were introduced to the Melbourne railway system in 1981. Initially, along with the Glen Waverley line, they were only allowed to operate on the Alamein, Belgrave, Dandenong and Lilydale lines, due to the width of the trains (). Also in 1981, Glen Waverley line services commenced operations through the City Loop, after previously terminating at Flinders or Spencer Street stations. The commencement of operations involved the service stopping at three new stations—Parliament, Melbourne Central (formally Museum), and Flagstaff. The Loop follows La Trobe and Spring Streets along the northern and eastern edges of the Hoddle Grid. The Loop connects with Melbourne's two busiest stations, Flinders Street and Southern Cross, via the elevated Flinders Street Viaduct. Many stations were rebuilt and level crossings removed along the corridor through the construction of road bridges during the 1970s to the late 1980s. These works coincided with the construction of the Monash Freeway which runs alongside the route for part of the journey. 21st century In 2014, the Level Crossing Removal Project announced the removal of 2 level crossings on the Glen Waverley line, to be completed in 2016 and 2020. The removal of Burke Road, Glen Iris involved the lowering of the rail line and the reconstruction of Gardiner station. This was the first crossing to be removed by the project and was completed in 2016. The second removal involved raising the rail corridor above Toorak Road, Kooyong, with the crossing removed by early 2020. With the removal of 2 level crossings along the corridor,