ONLY a driver's quick reactions prevented a serious accident when a man, desperate for a smoke, ran across the lines in front of his train, a court heard.

Harrogate magistrates were told how Northern Rail 9.21pm Leeds to Knaresborough express was crossing the viaduct over the River Nidd when Michael Goodair decided he needed a cigarette.

Prosecutor Peter Scott said 26-year-old Goodair was standing on the westbound platform at Knaresborough station waiting for a Leeds train when the incident occurred.

As the train approached Goodair, of Moseley Wood Green, Cookridge, Leeds, jumped down on to the tracks and crossed to the opposite platform.

The driver slammed on his emergency brakes to avoid a collision. But when he went to ask a signalman to call police, Goodair and another man ran off into the town.

Goodair told police investigators later that he had been offered a cigarette on the opposite platform, but realised he had ''done something wrong'' so left the scene.

Hepleaded guilty to obstruction by jumping on to railway tracks in front of a moving train and apologised.

He said his danger dash followed a drinking session in which he had had eight pints.

The father of two said he had since thought long and hard about his actions and what might have happened.

Goodair was fined £150 with £45 costs.