Transport called before the Transport Select Committee. The Transport Select Committee published its report into various matters including regional investment disparity on the railways and calling again for the reinstatement of various cancelled electrification schemes. A written question was submitted and answered in parliament regarding route miles electrified in the years 1997–2019. In March 2019 the Railway Industry Association published a paper on Electrification cost challenge suggesting ways forward and a rolling program of electrification. Future of third rail In June 2011 Peter Dearman of Network Rail suggested that the third-rail network will need to be converted into overhead lines. He stated: "Although the top speed is , the trains cannot go over well and 25% of power is lost from heat." Agreeing that conversion would be expensive, he said that the third rail network is at the limit of its power capability, especially as trains become more advanced in technology. The July 2012 Department for Transport High Level Output Specification for Network Rail Control Period 5 includes the conversion of the South West Main Line between and from 750VDC third rail to 25kVAC overhead as part of a scheme to improve rail freight capacity from Southampton Port. This conversion would be a pilot scheme to develop a business case for full conversion of the third-rail network. The Office of Rail and Road (ORR) has also stated that, on safety grounds, third-rail 750VDC has a limited future. Existing systems – overhead line (OHL) National Rail: 25 kV, 50 Hz AC overhead British Railways chose this as the national standard for future electrification projects outside of the third rail area in 1956. Following this, a number of lines that were originally electrified at a different voltage were converted, and a number of lines have been newly electrified with this system. Work started in the late 1950s. The first major electrification project using 25 kV was the West Coast Main Line (1959–1974). Initially this was Crewe, Manchester and Liverpool south into London and Birmingham. Weaver Junction north to Glasgow followed later. The 25 kV network has been gradually expanded ever since: Existing Great Western Main Line Electrified from London Paddington via , and to . Electrified from to . Electrified from London Paddington to in 1994 in a joint venture between British Rail and the British Airports Authority using the Mark 3B series. West Coast Main Line Electrified from London Euston during