When the police stop a motorist and suspect alcohol consumption, the motorist is required to provide a breath test at the roadside. The roadside device simply gives a general indication of the level of alcohol present in the system. If the device shows alcohol above a certain level, the driver is arrested. At the police station a further breath test is required on a more sensitive device, or alternatively a blood sample. If the motorist refuses a sample of breath or blood, he is charged with that refusal.
An innocent driver was arrested when a roadside breath-testing device showed twice the permitted level of alcohol, according to an article in the Telegraph today. At the police station, it was discovered that the driver had not consumed any alcohol. The roadside device was obviously faulty.
If the motorist had refused to submit to the police station procedure, a much more sensitive breath testing machine (on the basis, perhaps, of knowing he had had nothing to drink), he would have been charged with failure to submit to the test, and it would never have been discovered that the roadside device was faulty. So think twice before refusing a breath test – whatever the circumstances — and be aware that the roadside devices can be faulty.