Intelligent speed assistance for serious speeders: The results of the Dutch Speedlock trial

One of the most important policy questions regarding Intelligent Speed Assistance (ISA) is whether or not it should be implemented, and if so how. In 2010 the Dutch Ministry of Infrastructure and the Environment decided to perform a field operational test to investigate the possibility of using ISA as a penalty system for serious speed offenders. This paper presents the results of this research, focusing on the effects on road safety. The results show that the two types of ISA systems that were tested have a huge effect on driver behavior and have the potential to improve road safety by reducing the level of speeding, mean speed, as well as the standard deviation of speed. However, the users show little sign of learning after the systems are turned off. Moreover, the serious offenders frequently use the emergency button to override the system which might seriously affect the efficacy of the system.