Drivers suspected of being under the influence of drink or drugs will be asked to stand on one leg in roadside tests throughout Cumbria.
Police are introducing the impairment tests as new figures reveal that the number of drink drivers has doubled in the last five years from 86 to 160.
They will also be asked to walk in a straight line and have their pupils examined during the summer campaign.
Those involved in car crashes will also face breath tests.
Insp Nicholas Coughlan, of Cumbria Police roads policing unit, said: "Throughout the summer months the incidents of drink driving increase as people go out to enjoy the weather and a few drinks.
"We are not trying to stop people enjoying themselves we just want drivers to act responsibly.
"If you are going out, nominate a driver who agrees not drink before you set off and always remember that if you've been drinking the previous night you may still be over the limit the following morning."