Alcohol and drugs affect your ability to drive safely, and increase your chances of having a crash.
The police are allowed to stop you at any time and ask you to do a random breath test (RBT) or a saliva test. A random breath test will show if you've been drinking alcohol. A saliva test will show if you've been using certain drugs. If you fail one of these tests you can lose your licence and be fined heavily.
Click here for an information sheet on alcohol and drug screening.