During the last years, Quebec and French Ministry of Transport have incorporated the road safety audit in order to renew assessment methods of road infrastructures. Road safety audit reaches to transcend limits of technical knowledge by the use of driver experiences in an interactional expertise framework (Collins & Evans, 2007). In this way, road safety audit appears as a radical cognitive transformation. But, during this empirical study, we highlighted the predominance of technical knowledge in the interactional expertise. We analyse this technical centrality by the return of road safety engineering cognitive traditions (Giddens, 1994). So, the interactional expertise, used in the audit, seems to be less a cognitive change than a transformation of the expert social role in front of a new social order.
In this way, this paper will present first of all, the interactional expertise as the consequence of three structural transformations: the sub-politicization of road safety field, the French and Canadian devolution policies and the neoliberal turning point of public action. Then, we will analyse the position of driver knowledge in the expertise in front of the return of technical tradition, specifically in the drawing up road safety audit report. Finally, we will show that road safety audit is used to ensure new forms of legitimacy: impartiality legitimacy in Quebec and proximity legitimacy in France (Rosanvallon, 2008).