Sir, - I write in strong support of Liam Kidney's letter (February 7th) about the danger of unlit tractors on Irish roads. Last year I was driving through Monaghan in the gathering dusk when I almost ran up the backside of an unlit, muck-spattered tractor and trailer. I upbraided the driver for not having any lights. His answer? "Sure, I know where I'm going!" - Yours etc.,Nigel Cooke, Whyteleafe, Surrey, England.