The Police Service of Northern Ireland follows National Police Chiefs’ Council (NPCC) guidance known as the ‘10pc plus 2mph’ rule, under which enforcement would usually begin at 35mph in a 30mph zone.

However, the PSNI warned that the guidance is not law and does not give drivers permission to exceed the speed limit.

The force said: “As specified by the National Police Chiefs’ Council, the 10pc in excess of the speed limit plus 2mph rule is in guidance, but is not part of legislation.

“It is used as a discretionary rule of thumb to ensure that enforcement is proportionate.”

Police can still take action against motorists travelling below the recommended threshold.

Chief Inspector Celeste Simpson, head of road policing at the PSNI, said: “Speed limits are just that – limits, not targets – and we continue to appeal to all drivers: please do not speed. Even going a couple of miles in excess of the speed limit means you have less of a chance to react to the unexpected on the road. It’s just not worth it.”

She described speeding as one of the “fatal five” road traffic offences, alongside drink or drug driving, not wearing a seatbelt, mobile phone use and distracted driving.

“Since January 1 this year, 54 people have lost their lives as a result of road traffic collisions in Northern Ireland. These are devastating losses. Lives changed in an instant and forever,” she said.

“The number of people dying on our roads is unacceptably high.”

She added: “Together, by making safer choices, we can help keep our roads safer for everyone and reduce serious and fatal road collisions on our roads.”

The PSNI’s website states that an offence occurs at 1mph above the speed limit, although enforcement tolerances can vary and change without notice.

Earlier this year, the Belfast Telegraph reported that an average of 240 motorists were caught speeding every day in Northern Ireland. A total of 87,443 speeding detections were recorded in 2025, according to the Northern Ireland Road Safety Partnership.