A month-long crackdown on drink-drivers saw more than 100 motorists being arrested.
The national campaign targeting those who get behind the wheel under the influence of drink or drugs was launched on June 1.
National figures released show more than 60,000 roadside breath tests were carried out during the month, resulting in more than 5,000 arrests being made.
In the Durham and Cleveland force areas a total of 419 tests resulted in 102 arrests.
Police say the high percentage was almost certainly due to the vast majority of tests being conducted following a road collision or where the police had cause to believe the driver was unfit through alcohol or drugs.
Insp Wendy Tinkler, from the joint Cleveland and Durham Specialist Operations Unit, said: “While it is still disappointing we found more than 100 drivers willing to risk their safety and the lives of others, it demonstrates our efforts in targeting this issue paid off.”