West Midlands Police is concerned drivers are still not getting the drink-drive message after it recorded more positive tests and dealt with a "significant" rise in collisions in December.
Almost 16 per cent of drivers tested in this year's drink/drug-drive campaign were over the limit. This year's targeted campaign ran for the entire month of December, an extension on last year's campaign, which ran only for three weeks.
More than 20,000 motorists were stopped, of which 3,536 were breath-tested, with 552 positive results - 313 more than last year when 3,289 were tested.
Two people were also dealt with for driving while under the influence of drugs, the same number as last year.
The force said there was a rise in the number of injury collisions this year, with a total of 391 collisions, an increase of 252 on last year.
However, it added bad weather may have been more of a factor for the increase because the number of positive breath tests from injury collisions fell slightly from 21.6 per cent to 21 per cent.
Chief Inspector Steven Palmer, head of force traffic, said: "The drink-drive message does not appear to be getting through.
"People are still drinking and driving and the number of people testing positively following a collision is one-in-five.
"While more people were tested this year than last year and we targeted particular hotspots, over double the number of people tested positively.
"We run random drink-drive tests throughout the year so just because Christmas is over, it does not mean that drivers over the limit will not get caught."