Capita Symonds completed their Mid Wales Rail Utilisation Study for TraCC in April 2010. This considered a range of potential improvements to rail services and facilities, including the provision of new stations. Each scheme was evaluated on a common basis, with an outline business case being developed in accordance with Stage 1 of the Welsh Transport Appraisal Guidance (WelTAG).
The WelTAG Stage 1 appraisal of Carno station predicted that the new station would generate about 6300 new trips per annum, significantly more than the figure predicted in the Carno Transport Appraisal (3700). The capital cost of a new station with a 97 m long platform suitable for 4 car trains was estimated at £0.95 m, which is in line with the £1.0 m figure assumed in the Carno Transport Appraisal.
The appraisal included an estimate of financial Benefit Cost Ratio in terms of the projected fare revenue divided by the sum of station capital and operating costs, with all revenues and costs discounted back to a common datum year. However, application of an uplift of 50% to the station capital cost – in order to account for “optimism bias” – reduced the Benefit Cost Ratio to 0.75. The additional revenue accruing to Carno station from existing rail journeys abstracted from Caersws was not included.