Police in Lancashire have started a crackdown on drink and drug driving.
During the month-long campaign, police will stop drivers at various key locations and administer drink and drugs tests, a spokesman said.
Last year, 46 people were killed in crashes in Lancashire. Eight of those involved drink or drugs.
In a similar campaign last year, 9,000 people were tested. Two hundred and 20 failed or refused the test. Police say they want to see that number decrease.
Supt Peter O'Dwyer, of Lancashire Police, said: "We want people to have fun this summer and enjoy the warmer weather but to remember the dangers of driving whilst under the influence of alcohol or drugs.
"The consequences of drink-driving are high - a conviction could mean that you lose your job, home, family and friends.
"Not only that but you are more likely to cause a road crash than a driver who hasn't been drinking, potentially resulting in serious injury or even death."
Councillor Tim Ashton, Lancashire County Council's cabinet member for highways and transport, said: "A great deal of effort has gone into reducing the numbers of people being killed and seriously injured on our roads through safety engineering works, driver training and education.
"But individuals also have to take responsibility, and decide for themselves that the risk of drinking and driving is one that's simply not worth taking."