What happens if PSNI stops me on suspicion of drink driving?

Under Northern Ireland road-traffic law, police can require a preliminary breath test where they reasonably suspect alcohol, after certain moving traffic offences, or following a road collision. PSNI also runs targeted drink-drive operations.

If the roadside indication gives police reasonable grounds to suspect you are over the prescribed limit, you can be arrested and required to provide evidential specimens. The evidential process can involve two breath specimens or, in specified circumstances, blood or urine.

Do not confuse the handheld roadside result with the final evidential result. The investigation and charging decision are based on the statutory process and admissible evidence, not simply on how intoxicated a driver appears.

The NI enforcement process separates screening from evidential proof. A roadside breath test, DrugWipe or impairment check gives police information and may justify arrest or further testing, but the prosecution is built from the statutory evidential procedure, officer observations and any laboratory or approved-device result. That distinction matters when reading reports of someone having “failed a roadside test”. For the vehicle or licence holder, this means pSNI can require preliminary testing where the legal grounds are met; a positive or failed test can lead to arrest and evidential testing for a drink-driving investigation. Where dates, categories or vehicle status matter, keep the original paperwork because those details can change the result.