High Quality Content by WIKIPEDIA articles! Network Rail (NR) has an obligation, transferred from the abolished Strategic Rail Authority, to periodically produce Route Utilisation Strategy (RUS) documents. The current programme was approved by the Office of Rail Regulation (ORR) in June 2006; under an early version of the programme all but two RUSs were scheduled to be completed by the end of Control Period 3 (CP3), 31 March 2009. The programme is reviewed by NR and ORR at regular intervals; despite this the delivery timescales have continually slipped. At the end of CP3 no fewer than 9 (almost half) remained incomplete (still in progress or not yet established), despite the fact that funding for infrastructure developments in CP4 was largely set.