Christina Fraser was a passenger in the car hit by the digger
Appeal judges have increased a haulage firm's fine of £3,750 to £30,000 to "bring home" the consequences of an accident that led to a woman's death.
A 30-tonne digger rolled off a transport lorry and hit a car killing passenger Christina Fraser, 24, on the A9 in Ross-shire in July 2006.
Munro & Sons (Highland) Ltd admitted a breach of health and safety law and was fined last April.
But the judges sitting in Edinburgh said the penalty was too low.
Lord Nimmo Smith, who gave the appeal court ruling at the Court of Criminal Appeal, said the lorry driver, Walter MacLennan, was not to be blamed but the fault lay with individuals higher up in the company.
The judge said: "The consequences of Munro's corporate error of judgement were catastrophic and need to be brought home to Munro's directors."
Scotland's senior judge, the Lord Justice General, Lord Hamilton, said the original fine "took inadequate account of the nature of the offence itself and the need for appropriate punishment in the public interest".
Ms Fraser had been getting a lift home with a colleague from her beautician's job in Inverness when the accident happened between Tain and Alness.
Her husband-to-be came across the accident while driving to play football.