A judge has criticised Nottinghamshire police after a senior officer caught speeding was initially only cautioned.
Supt Helen Chamberlain drove at 79mph in a 50mph area but the decision to prosecute was only taken later.
At Nottingham Magistrates' Court she admitted speeding and received six points on her licence and fines and costs of £1,500.
District Judge Tim Devas said only in their "wildest dreams" would most people expect not to be prosecuted.
Ms Chamberlain, from Harworth, was stopped on a section of the A6097 Epperstone bypass between Epperstone and Oxton last July.
The constable gave her a roadside caution, a decision which was later overruled by more senior officers.
The judge said the first decision "doesn't reflect very well on Nottinghamshire Police".
He continued: "Can you imagine in your wildest dreams a police officer telling one of us: 'You are not going to be prosecuted for being 29 miles an hour over the limit?'
"The public might think it was because of who she was."
Nottinghamshire Police said it enforced the law "without fear or favour" and was considering disciplinary action against Ms Chamberlain.