Abstract
Opinions differ on the question if one-way schemes in urban areas improve traffic safety or make it worse. For this reason an investigation has been carried out in four large Dutch cities, on the effect on traffic safety, of the introduction of one-way schemes, compared with those areas where such schemes have not been introduced. It appears that one-way traffic in general has neither a favourable nor an inverse effect on the total number of accidents. Making a statement about the effect on the seriousness of accidents was not statistically justifiable.