ABSTRACT
Integrated systems design should anticipate potential occurrences of inadvertent aberrations and build in safety measures to ensure that even breakdown of certain components does not result directly in crashes. In case of technical system failure, the road user should still be able to cope with the situation in one way or another; and in case of human failure the road system should be robust in design and meet the sustainable safety principle of forgivingness of the environment and/or of road users. But not only human error should be considered. More technical components of the system may fail and the design should also be such that system failures are recognized in time by the road user so that with the information available they are still able to act appropriately given the conditions. Compared to traditional priority intersections, roundabouts appear to be a sustainably safe solution, with an average reduction in accident occurrence of between 30 and 50 per cent.
