If a police constable reasonably suspects you are/have been driving, attempting to drive or in charge of a motor vehicle on a road or public road and:
- You are under the influence of alcohol or drugs e.g. breath smells of alcohol, or
- You have committed a moving traffic offence e.g. going through a red light, or
- You have been involved in an accident
The PC can require that you take a preliminary breath test, field impairment test (FIT) or chemical drug test - PC must be in uniform to conduct these tests but not following an accident.
The police cannot stop a vehicle just to carry out a random breath test. They have to have a reasonable suspicion that the person has consumed alcohol or drugs. However, once the vehicle has been stopped for, perhaps, a routine check, this can be ascertained through the smell of alcohol, slurred speech or glazed eyes etc. Failure to comply with a request to carry out a breath test is an offence and the penalty is the same as if you had been convicted of being over the limit.