"The Government's role in the running of the railways is to provide strategic direction and to procure rail services and projects that only it can specify. To fulfil this role, DfT's Rail Group is working in partnership with the industry to secure the railway the country wants at a price it can afford and the Deputy Director, Rail Systems is a key appointment." (link below.)
http://www.dft.gov.uk/about/recruitment/secdftvacancies/deputydirectorrailsystems