Illogical speed limits

Sir, – We recently drove from Dublin to Waterford, taking the coastal route for a change. Having detoured through Camolin, Co Wexford, for a coffee stop, we found ourselves on the old N11 – a fine, wide, straight road with considerably reduced traffic since the opening of that stretch of the M11. This road, on which it has always been considered perfectly safe to travel at 100km/h, is now downgraded to an 80km/h speed limit. The next stretch of our journey took us onto the N30 between Clonroche and New Ross. This is a narrow, single-carriage road, with no hard shoulder and numerous nasty, twisty bends which have witnessed several tragic accidents. The speed limit on this road? 100km/h. Can anyone explain to me the logic of these limits? – Yours, etc,

SALLY SWEENEY,

Carrigavantry,

Co Waterford.