This is an operational matter for Network Rail as the owner and operator of the national rail network. The noble Lord should contact Network Rail's chief executive at the following address for a response to his Question: John Armitt, Chief Executive, Network Rail, 40 Melton Street, London NW1 2EE.
Franchise agreements contain contractual minimum performance requirements, and in the case of sustained poor performance by a train operator below this level, an agreement can be terminated.
For First Great Western, the contractual performance measures used are delay minutes and cancellations (measured on a moving annual average basis) compared with the benchmarks in the franchise agreement; the non-contractual measures are the public performance measure and progress against the non-contractual joint performance improvement plan targets.
In its invitation to tender for the Greater Western franchise, the former Strategic Rail Authority specified a minimum train service pattern. Bidders were required to form their own views of existing and future demand, and to respond with proposals, including rolling stock deployment, to meet this demand.