A further £1.7 million at least will be needed to build a new station at Low Moor, it has emerged, meaning more trains must visit the new station in order to make a strong business case to justify the £7.2m total outlay.

The knock-on effect of increasing to three trains per hour at the proposed station is that the current proposal for 117 car park spaces will need to triple. Transport authority Metro has updated its assessment of parking provision to support the new figures of around 350.

The move comes as it emerged that the planned completion date for the station was put back another year to 2015.

The extra expense on top of the budgeted £5.5m cost for the new station is down to three problems: the presence of old mineshafts significant ground slopes and a difficult topography of the car park site and trackside access previously unidentified gas pipelines.

In addition a further £500,000 could be required as a result of changes to engineering safety requirements for building platforms on a curve, such as would be the case at Low Moor.

And the costs of providing extra car parking are as yet unknown.

Richard Gelder, transportation development manager at Bradford Council, explained in a report: “A budget of £5.5m has been allocated by the West Yorkshire Integrated Transport Authority for the delivery of the station at Low Moor. The latest estimated cost of delivery of the station currently stands at £7.3m (excluding £500,000 for dealing with the derogation issue and as yet unquantified additional capital costs for the larger car park) which exceeds the available budget.

“Whilst efforts are being taken to reduce the estimated cost of the scheme these are unlikely to bring costs down to within the available budget. Previously committed funding remains ring-fenced.”

James Vasey, chairman of Bradford Rail Users’ Group, said they welcomed the moves to increase the number of trains per hour, but was concerned about one of the proposed sites for extra car parking.

He said they would prefer the use of the Transperience site, which while further away from the station, is closer to the M606 and could become a park and ride spot, while keeping extra cars out of the village itself.

It is expected that a “robust solution” for the new station on the Caldervale Line, including a conclusion on route infrastructure and impacts on timescales, will be available by May 2013.