A new Forth crossing has been given the green light but it may not be built before the bridge is closed to LGV traffic from 2013.
Scotland's transport minister Tavish Scott could give no reassurances that the new crossing would be up before the existing road bridge is closed to trucks because of corrosion.
Bridgemaster Alastair Andrew is concerned about the time gap, saying: "We have a critical date of 2013 or 2014 to remove heavy goods vehicles. And yet our experience, and the experience of the consultants who are advising us, is that it would take between 10 and 11 years for us to deliver a new crossing of the Forth."
RHA director for Scotland and Northern Ireland Phil Flanders warns if the new crossing is not ready trucks must make long detours that may cost up to £50 for each journey due to extra fuel and time.