Sir, – Dr Jarlath Molloy (March 9th) asks why the NRA and Meath County Council do not impose a heavy goods vehicle ban on Slane bridge. Could the answer be that it would be the cheapest and most aesthetically pleasing solution to the problem or could it be that if such a ban were imposed that heavy goods vehicles would be forced to pay a toll on the shorter M1 route? – Yours, etc,