Safety learning and imagination versus safety bureaucracy in design of the traffic sector

This paper deals with the processes of evaluating the possible safety effects of measures introduced either in the road infrastructure or in the electronic and information systems in cars. It uses speed control measures (speed bumps and the Intelligent Speed Adapter [ISA]) as cases to describe and test the approach. The paper describes and critically assesses the current methods of ex-ante design and evaluation of such measures, which relies on design to national and international standards. It criticises this approach, particularly from the point of view of predicting unexpected and unwanted effects of the new designs. It proposes an adapted form of hazard and operability study as a tool to help predict these effects and validates this approach against the experiences of a field study of an ISA instrument.