A simple plan of widening the footpath in the Port Tunnel would increase the operational clearance for trucks using the tunnel from 4.65 metres to 5.05 metres and allow "supertrucks" to use it, according to the Transport Umbrella Group (TUG).
The widening of the footpaths to the standard width used by the National Roads Authority (NRA) would force trucks into the centre of the carriage way ensuring that they would gain the operational clearance required from the arch of the tunnel. The current footpaths are less than the NRA standard for other roads around the country.
The plan was drawn up by an independent engineer, Mr Cormac Rabbitt, hired by TUG to find a proposal that would allow supertrucks, also known as "supercubes", to use the Port Tunnel. If plans for the tunnel remain the same then supercubes would resort to using the streets of Dublin.
A supercube vehicle can hold twice the amount of an articulated truck even though it is only 18 inches higher.
According to Mr Rabbitt, the cost of the modifications would be very small.
TUG also claims that the NRA's current plans for the Port Tunnel do not conform with 230 other bridges and tunnels around the country and that Mr Rabbitt's plan would bring the tunnel in line with the NRA standard.
The plan will be presented to the Minster for Transport, Mr Seamus Brennan and also to the Joint Transport Committee tomorrow.
The group also rubbished claims that less that 1 per cent of trucks would be affected.
Chairman of TUG, Mr Jerry Kiersey said: "No scientific study has been carried out on truck heights by anyone. The NRA have no database on truck heights".
Mr Rabbitt added: "Could you imagine any supermarket that did not know what its customers wanted? That's what we have here".