Abstract Drink driving is an infamous factor in road crashes and fatalities. Alcohol testing is a major countermeasure. and random breath tests (RBTs) deter tested drivers and passersby (observers who are not tested). We propose a genetic algorithm (GA)-based RBT scheduling optimisation method to achieve maximal deterrence of drink driving. https://fitnessgravesyardes.shop/product-category/left-side-sticker/