Politicians condemn plans for new bridge as report finds current crossing could be repaired

The Scottish government's £1.6 billion plan for a new road bridge across the Firth of Forth will bring traffic "gridlock" to Edinburgh, triggering an economic and environmental disaster.

That is the dire warning being sounded this weekend by the City of Edinburgh Council, which is run by a coalition of LibDem and SNP councillors. They have all backed a report from officials that condemns a new bridge, and are meeting with ministers to express their concerns in October.

The SNP government has given the go-ahead in principal to a new crossing, and is currently awaiting the results of a consultation by Transport Scotland on whether it should be a bridge or a tunnel. Because it is cheaper, a bridge is the favoured option.

Although it is called a "replacement" bridge, most observers now believe that if it is built, it will be in addition to the existing road bridge. The latest analysis from the Forth Estuary Transport Authority suggests that it will be possible to repair or replace the support cables which are suffering from corrosion.

Edinburgh council's report says that it now appeared "almost certain" that the existing bridge could be repaired. It expresses "serious concern" that the economic appraisal conducted for Transport Scotland failed to take account of scenarios in which the bridge remained open.

The council is also angry that Transport Scotland failed to consult with local authorities on its plans. "It is premature to take a final decision on constructing a new crossing or on the form any new crossing should take," its report concludes.

The prospect of two four-lane bridges running across the Firth of Forth alarms Edinburgh council.

Its report estimates that this could double the amount of traffic heading into the city during peak hours.

According to the council's transport convener, LibDem councillor Phil Wheeler, this would cause "gridlock" in western Edinburgh. "Our ambition to create a free-running and green city would be jeopardised," he told the Sunday Herald.

Like the decision to abolish the bridge tolls, opting for a new bridge looked like "a rushed, knee-jerk response to election results, the consequences of which had not been thought through", Wheeler alleged.

The original decision in favour of a new crossing was taken by the previous Scottish Executive after Labour lost the Dunfermline and West Fife by-election to the LibDems in February 2006. Some in Labour blamed the shock defeat on dithering over a new bridge, strongly favoured by people in Fife.

Green councillor Steve Burgess, a member of the transport committee, said it was "appalling" that the council hadn't been consulted. "There's no doubt the economic and environmental consequences of an additional bridge would be disastrous," he argued.

The council's criticisms have been echoed by the National Trust for Scotland, one of the country's most powerful conservation organisations. In a submission to Transport Scotland, the Trust has concluded that "the case for an additional crossing has not yet been made".

The Trust's head of policy, John Mayhew, pointed out that increasing the road space for private cars was in conflict with government policy to cut the pollution that causes global warming. He also criticised the use of the phrase "replacement crossing" as misleading because the existing bridge was likely to be refurbished.

"If we are really to have one rail bridge and two road bridges in future, then they should really come clean and describe it correctly as the Forth additional crossing," he said.

According to Transport Scotland, the Forth Replacement Crossing Study considered that the existing bridge may have to close to heavy goods vehicles as early as 2013 and to all traffic by 2019. It had examined ways of managing traffic crossing the Forth to improve reliability and travel choices while minimising the impact on both people and the environment.

"A range of multimodal options are included in the study, including use of the existing bridge," said a Transport Scotland spokesman. "If two crossings are in use, there would not be greater provision for single-occupancy vehicles than currently exists across the Forth." Decisions on whether to use the existing Forth road bridge "will form part of the decision on the Forth Crossing to be made by ministers before the end of the year", the spokesman added.