The long-term effect of Intelligent Speed Adaptation on driver behaviour.

This paper investigates the impact of prolonged experience with an Intelligent Speed Adaptation (ISA) system on driver behaviour. ISA refers to a driver support system which brings speed limit information into the vehicle. Drivers' interaction with the ISA system was explored by means of data collected from long-term field trials carried out in the UK and Sweden. Results indicated that participants' overriding behaviour increased in line with system exposure. However, there was no strong evidence supporting a generalised turning point of behavioural changes (e.g. 3000km, 4000km, or 5000km accumulated experience) at which the upward trend plateaued. Driver characteristics were found to be influential on the pattern of overriding the ISA system with respect to subjective measures (intention to speed) as well as objective measures (observed speeding behaviour). Driving environment also demonstrated an impact on participants' overriding behaviour. Implications for driver behavioural changes in the presence of a generic ADAS are discussed.