Risk of apprehension for road traffic law violations in Norway.

Violations of road traffic law are widespread in all countries. Probably the most common violation is speeding. It is not uncommon that 50 % of vehicles are speeding. Little is known about the risk of apprehension for various traffic law violations, although it is often assumed that nearly all violations go undetected. This paper quantifies the risk of apprehension for common traffic law violations in Norway, based on data for the period 2006-2022. The violations included are speeding, non-use of seat belts, driving with an illegal blood alcohol concentration (above 0.02 %), driving while impaired by medicines or illegal drugs, use of a hand-held mobile phone while driving and violations of the regulations of hours of service and rest for drivers of heavy vehicles. Risk of apprehension is stated as the number of detected violations per million vehicle kilometres driven while committing the violation. The risk of apprehension is in most cases between 10 and 50 per million vehicle kilometres driven while committing a violation. This is quite low. For speeding, the risk of apprehension was between 10 and 12 per million vehicle kilometres of speeding during 2006-2022. For an average driver, this means that he or she could speed on every trip for about 8-10 years before getting caught. Reducing traffic law violations may contribute to a large reduction of the number of traffic fatalities.