The 2008 Periodic Review (PR08) set the outputs that Network Rail must deliver, and the level of access charges paid by train operators for use of the infrastructure from 1 April 2009 to 31 March 2014, or control period 4 (CP4).
The assessment of the scope for Network Rail to improve on its cost efficiency is central to our work, since it enables us to establish efficient levels of track access charges when we periodically review Network Rail's outputs as part of a balanced package.