In rejecting the case for a full loop service on the Henbury line (Bristol Post, 9 July), the consultants would appear to have based their conclusion on pessimistic forecasts of passenger numbers and revenue. It is difficult to believe that a loop service, linking heavily populated areas of West and North Bristol, would attract only 8,000 more journeys per year than a service turning round at Henbury, and deliver additional revenue of only £30,000 is its third year. The basis of this calculation needs to be made public; the effect on passenger numbers of doubling train frequency at stations between Avonmouth and Temple Meads seems to have been ignored. Avonmouth station itself gained 13,000 passengers in the most recent year (2013 /14) for which the Office of Rail and Road has published figures of station usage and that was without any increase in train services. ORR statistics reveal a remarkable increase in recorded journeys at Bristol’s 12 existing stations from a total of 4.1 million in 1997 /98 to 11 million in 2013 / 14. Over the same period total journeys at the six stations in South Gloucestershire grew from 1.5 to 3.8 million.

An enhanced train service between Swindon and Westbury, giving eight trains each way instead of two, was introduced in December 2013 and was predicted to attract 45,000 passengers in the first year. 183,000 were carried according to First Great Western. This would suggest a latent demand for rail travel which does not appear to be accepted by some planners and decision makers.

The loop option was not considered without a station at Constable Road, which would have improved the business case. However the key reason that the loop performs badly in the comparison is the assessment that three rather than two units are required to provide an hourly loop service in each direction, even though the unconstrained journey time around the loop from Temple Meads is between 50 and 54 minutes, because of the fixed timings on the Severn Beach line and pathing constraints on Filton Bank. This means that loop services in opposite directions arrive at either Henbury or Temple Meads at the same time, so removing the opportunity for an hourly loop service in each direction to effectively provide two trains per hour from Henbury to Bristol. It also has the effect of disproportionately increasing the operating costs when compared with the single unit required for a hourly turnback service.

It is difficult to understand why pathing will be so constrained after Filton Bank has been quadrupled, or why Severn Beach service timings cannot be changed, or skip-stopping introduced on the Severn Beach line, or the loop service combined with services going south from Temple Meads, so that the loop service can be provided reliably with only two units. Other conurbations such as Glasgow, South Hampshire and Tyneside have loop rail services which economise on rolling stock and maximise journey opportunities. The apparent constraints in Bristol need to be challenged.

It is widely accepted that there is a high incidence of ticketless travel on Bristol’s suburban railways. This should not be an excuse to talk down the prospects for new rail services but an incentive to improve revenue protection. Only seven years ago the Government turned down plans to redouble the Swindon - Kemble line, one of Gloucestershire’s rail arteries but campaigners carried on the fight and the work was completed last year. We must not give up on the Henbury loop.

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