Report numberRA-MOW-2010-005
TitleAcceptability of Intelligent Speed Adaptation (ISA).
SubtitleConceptual framework and first results.
AuthorsSven Vlassenroot
Johan De Mol
Vincent Marchau
Karel Brookhuis
Frank Witlox
Published byPolicy Research Centre for Mobility and Public Works, track Traffic Safety 2007-2011
Number of pages32
Document languageEnglish
Partner(s)Universiteit Gent
Work packageOther: Sustainable transportation

A key success factor in the future implementation of new in-vehicle technologies is in understanding how users will experience and respond to these devices. Although it is recognized that acceptance, acceptability and/or support is important, consistency in the definition of acceptability, and how it can be measured, is absent. In this report we conceptualize acceptance as the attitudes towards a new device after its introduction and acceptability as the attitudes to it before its introduction. It is our goal to describe and conceptualize the most common and relevant socio-psychological factors that can influence acceptance and acceptability of Intelligent Speed Adaptation (ISA). Several trials with different types of ISA have shown that ISA can be an efficient and effective way to reduce speed and speeding.


By analysing the different theories and methods used in ISA trials we arrived at the 14 most potential indicators that could influence the definition of acceptability and acceptance.


In our research we asked the question will there be acceptability of ISA by the public? 6370 individuals responded in Belgium (Flanders region) and 1158 persons in The Netherlands on a web-survey. In our survey the respondents indicated that their own driving behaviour is of great influence on accidents and traffic safety, instead of environmental issues like infrastructure or even other drivers. Even more, the respondents indicated that ITS could be beneficial to support their driving behaviour. It was noted that there is a high market potential for Advanced Driving Assistance Systems (ADAS).


95% of the respondents are in favour of ISA.  Seven out of then drivers want to have an informative or warning system. Three out of ten drivers wanted to go even further and choose to have a supportive or even a restricting type of ISA.  Drivers would only choose for more restricting systems if the penetration level is high enough.

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The Policy Research Centre for Traffic Safety carries out policy relevant scientific research under the authority of the Flemish Government. The Centre is the result of a

cooperation between Hasselt University, KU Leuven and VITO, the Flemish Institute for Technological Research.


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