The relation between public lighting and the number of traffic accidents is of major importance in all countries, in view of the serious and alarming casualties and the increase in density and speed of traffic to be expected in the next few years. The proper function of public lighting is to convey the necessary visual information to road users clearly, completely and with the right emphasis. But the mechanism of traffic accidents implies that the connexion between the lighting and the number of accidents is necessarily tenuous, and to establish with adequate confidence a reduction of the accident rate requires the study of very large numbers of accidents. Accident rate requires the study of very large numbers of accidents. Accident studies must be made with rigorous statistical procedures, or they cannot be accepted with any confidence; many published studies are unsatisfactory for this reason. However, some satisfactory studies have established that the provision of good street lighting in traffic street previously badly lighted results in a reduction of personal injury accidents of the order of 30 per cent. In view of the mechanism involved in a traffic accident the Committee considers that valid information on the effects of lighting on accidents is not to be expected in much more detail than this; but the above result goes little further than conclusions drawn from general experience, and more information is needed both by civic authorities and by lighting engineers. A method now in hand which may give useful indications is outlined in the Report. Procedures are given for the collection of data of accidents which may increase the confidence in the results, and a suggestion is made for a valuable investigation which could be made in countries.
Abstract