Can a PSNI officer direct traffic even when the instruction conflicts with a road sign or signal?

Yes. Drivers must obey lawful signals and directions given by police officers, even where traffic is being temporarily managed differently from the normal signal or road-sign sequence.

For this Northern Ireland query, the practical issue is whether a PSNI officer direct traffic even when the instruction conflicts with a road sign or signal. A roadside stop in Northern Ireland should be treated as a legal compliance check, not as an argument at the roadside. The Highway Code for Northern Ireland states that drivers must obey police stopping signals and stop as soon as it is safe. PSNI can then check the matters for which it has legal powers, including driver entitlement, insurance and vehicle condition.

If stopped, pull over safely, switch off the engine when directed, answer lawful requests accurately and do not give false information. If a database record appears wrong, produce whatever genuine evidence you have and contact the insurer or issuing authority promptly. Disputes about a notice, seizure or alleged offence should be dealt with through the proper review or court process rather than by refusing to comply at the roadside. For this question specifically — “Can a PSNI officer direct traffic even when the instruction conflicts with a road sign or signal?” — the safest answer is the one above, based on the current Northern Ireland and UK official guidance rather than forum advice or rules written for another jurisdiction.