THE RELATIONSHIP BETWEEN ROAD LIGHTING QUALITY AND ACCIDENT FREQUENCY

Many studies have related changes in accident frequency to the presence of street lighting, and a few have examined its variation over a range of lighting quality, as measured by illuminance. This investigation attempts to find which of several measures of lighting (describing quantity - as represented by luminance or illuminance - uniformity and glare) most clearly explain variations in accident frequency. About 100 lit sites, almost all in built-up areas, were measured for lighting quality in dry-road conditions. The lighting variables measured were related to the dark:day ratios of accident frequency for the same sites. The strongest relationship found was that for average road surface luminance: in the range 0.5-2.0 candelas/m2, it is estimated that an increase of 1 cd/m2 is associated with a 35 per cent lower accident ratio. Other measures of luminance and illuminance were also found to be related to accident ratio (and to each other), but not as clearly as was average road luminance, which is therefore the preferred explanatory variable. Analysis of pedestrian and non-pedestrian accidents separately did not reveal a relationship between the former and lighting quality. In contrast, non-pedestrian accidents showed similar relationships to those for all accidents, with the addition of a possible relationship with overall uniformity of luminance.(a) (TRRL)

• Corporate Authors:

  Transport and Road Research Laboratory (TRRL)

  Wokingham, Berkshire  United Kingdom 
• Authors:
  • Scott, P P
• Publication Date: 1980

Media Info

• Features: Figures; References; Tables;
• Pagination: 19 p.

Subject/Index Terms

• TRT Terms: Crash rates; Crashes; Darkness; Daylight; Frequency (Electromagnetism); Glare; Luminance; Luminous intensity; Pedestrians; Quality control; Standardization; Street lighting; Surface course (Pavements); Surfacing; Urban areas
• Uncontrolled Terms: Quality
• ITRD Terms: 1643: Accident; 1612: Accident rate; 9008: Daylight; 6997: Frequency; 1677: Glare; 5916: Homogeneity; 545: Lighting (street); 525: Luminance; 9052: Night; 1733: Pedestrian; 9063: Quality; 2972: Surfacing; 313: Urban area
• Subject Areas: Highways; Pedestrians and Bicyclists; Safety and Human Factors; I85: Safety Devices used in Transport Infrastructure;

Filing Info

• Accession Number: 00322080
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Report/Paper Numbers: TRRL LR929 Monograph
• Files: ITRD, TRIS, ATRI
• Created Date: Jan 19 1981 12:00AM