As the White Paper states, the 0.45 square metres figure is one that has been in general use within the industry. It has been used for some time, in conjunction with other measures which are also described in the White Paper, as a rule of thumb when calculating train capacity. It was determined by the Strategic Rail Authority (SRA), based on earlier work by the British Railways Board.
(2) what methods are used by her Department and its agencies to calculate train capacity.
The Department for Transport’s calculation of train capacity is based on a consistently applied calculation, which uses the size of the interior of each passenger railway vehicle, divided by a space of 0.45 m2 which is an industry-standard calculation of the space occupied by each passenger.
Any structures, such as luggage racks are included in the calculation, and the total size of the vehicle interior is reduced accordingly to reflect where these structures exist. These calculations are updated when modifications are made to the interior of any fleet of passenger rail vehicles.