A delivery driver's carelessness was caused by exhaustion after three days of hiccups, a court has heard.
Paul David Bates was seen slumped over the steering wheel of his Citroën Picasso and clipped another vehicle, Carlisle Crown Court heard.
Police found he was unsteady on his feet, but there were no traces of alcohol or drugs in his system.
Bates, 48, was fined £130 and had nine penalty points put on his licence after admitting careless driving.
The court heard his gold car caught the attention of another motorist in Egremont, Cumbria, at about 19:30 BST on 14 September.
The other driver feared his vehicle would be hit from behind by Bates, who appeared to be slumped over the steering wheel and was swerving across the central white line.
The driver pulled over to let Bates pass, then rang the police and followed him providing a "running commentary" of his actions, prosecutor Tim Evans said.
More erratic driving followed and Bates, of Wellington, Seascale, clipped a vehicle in his home village before police caught up with him.
Officers felt Bates was "cognitively slow and unsteady on his feet".
He was initially unfit to be interviewed due to exhaustion, and spoke of being "utterly shattered".
Mr Evans said: "The defendant was claiming he had been suffering from a bout of hiccups for three consecutive days and had not been getting any sleep."
Recorder Eric Lamb praised the other driver for following Bates saying he should be "commended for his public-spirited actions".