[1] As Network Rail is responsible for developing and maintaining railway infrastructure, the Control Periods are used to decide priorities for investment.
In July 2015, Sir Peter Hendy was appointed Chairman of Network Rail "and asked by the Secretary of State to conduct a thorough review of the enhancement programme in England & Wales to see what can be delivered in an affordable and timely way within the funding period to 2019".
[9] In July 2017, the Department for Transport published the "high level output specification" for Control Period 6.
[16] In September 2019, Network Rail and the Department for Transport released the future of the Island Line, which include adding a new passing loop at Brading and upgrading Ryde pier and bring new trains to the Isle of Wight.
[18] As of the same date, Network Rail has not yet published its plan for Control Period 7, setting out the capital projects that it will deliver.