Abstract
Regular monitoring of the exposure of pedestrians and cyclists to traffic would enable one to calculate the risk per km or per road crossing of those forms of travel. This information would allow us to estimate the effect on accident rates of changes in modes of travel. It would also enable us to estimate the possible effects of safety measures aimed at pedestrians and cyclists. After a discussion of the costs and the advantages and disadvantages of various methods of monitoring the exposure of pedestrians, it is recommended that a combination of questionnaire techniques and observations at random sites will provide all the information required at the lowest possible cost.