Intelligent Speed Adaptation (ISA)

Intelligent Speed Adaptation (ISA), sometimes also referred to as Intelligent Speed Assist, is a technology that is designed to reduce the amount of time vehicles are driven above the speed limit and reduce the degree to which the speed limit is exceeded. ISA has three forms; limiting, supportive and advisory ISA. Previous studies have calculated a reduction in crashes by focussing on changes in speed profiles and the influence of travel speed on risk of injury. The aim of this study was to determine how ISA would directly affect the severity of a crash using information from event data recorders (EDRs). This study also included a literature review focused on previous ISA trials that examined factors that influence compliance with advisory and supportive ISA. It was found that ISA can result in substantial reductions in impact speed in a crash, and if all vehicles were fitted with ISA fatal and serious injuries would be reduced by 17.6% with limiting ISA, 8.1 to 12.3% with supportive ISA, and 5.1 to 9% with advisory ISA.