Page 19. The number of arrests for drink/drug driving offences in 2025 was 2,872, resulting in 2,794 drink/drug driving offences being referred for prosecution, with the worst offender being more than 5 times over the limit (Table 9). This is a decrease from 3,189 arrests and 3,125 offences referred for prosecution in 2016, a reduction of 10% and 11% respectively. Drink/drug driving continues to be a major contributor in fatal and serious injury road traffic collisions as ‘impaired by alcohol/drugs – driver/rider’ was the 3 rd most common principal causation factor for KSI casualties between January and November 2025 . Further analysis identifying issues and trends in relation to fatal and serious collisions caused by drink driving has been completed by Department for Infrastructure.