Studies have been reported on determination of effect of illumination of a roadway upon the night time accident rate. By careful analysis of traffic accident records, it is possible to show that accident rates at night are decreased as a result of improved lighting conditions. By examination of traffic accident reports received from the traffic section of the chicago park district, it is possible to show graphically the value and improtance of higher levels of street lighting in reducing the night time accident rate. Various before and after diagrams are shown. These indicate the fatal and non-fatal night accidents that were saved as the result of improved lighting. The main factors which would cause a variation of the night time accident rate are traffic volume and level of illumination. It is concluded that in a period of less than 5 years, the complete cost of relighting all boulevards would be balanced by the savings in night time accidents.
Abstract