Seven hundred people were stopped and tested in Norfolk during a drink and drug-driving crackdown over Christmas - and more than 30pc failed.
Of the 713 people tested by Norfolk police, 214 failed, an increase on last year's results.
The month-long campaign, which ran from December 1, 2019, targeted drivers getting behind the wheel under the influence of alcohol or drugs.
Across the county, 613 breath tests were carried out with 95 drivers providing positive readings.
Of the 100 drug tests conducted, 82 drivers failed.
Fifteen people also failed to provide a specimen and 22 were arrested for being unfit to drive through drink and drugs.
Chief inspector Kris Barnard, head of the roads and armed policing team (RAPT), said: "It's disappointing to see that people are still prepared to take the risk and get behind the wheel under the influence of alcohol or drugs.
"These people not only risk their own lives but the lives of others.
"We have first hand experience of having to deliver the devastating news to the families of those involved in fatal collisions that their loved ones have died.
"We would not wish this on anyone which is why we work hard throughout the year to tackle these crimes.
"Driving under the influence of drugs or alcohol impairs your judgement, making your reactions slower, and therefore increases the chances of being involved in a collision. The results from this year's campaign show that we will target those who pose a danger to themselves and others on our roads and that they will be dealt with."
Lorne Green, Norfolk's police and crime commissioner, said the latest results were "hugely disappointing". He said: "A momentary lapse in concentration can lead to disastrous consequences and it is hugely disappointing that, despite the warnings, so many drivers are still intent on flouting the law.
"We all have a part to play in keeping our roads safe. Dangerous driving kills - whether through excessive speed, being drunk or on drugs or not giving the road your full attention.
"Such carelessness is simply unacceptable and just not worth the risk.
"The life saved may even be your own."
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