Safety effects of street lighting on roadway segments: Development of a crash modification function.

CONCLUSIONS: Horizontal illuminance characteristics have a significant impact on nighttime crash risk on roadway segments. An increase in the mean of horizontal illuminance, indicating an improvement in average lighting level, tends to decrease nighttime crash risk; an increase in the standard deviation, representing a poor uniformity of lighting pattern on a roadway segment, is more likely to raise nighttime crash risk. Because the 2 measures are strongly correlated in a low mean range (<0.44 fc), the 2 photometric measures need to be considered together to interpret the safety effects of lighting patterns. The standard deviation shows better performance in measuring lighting uniformity on a roadway segment than the traditional ratios (max-to-min and mean-to-min). However, a new photometric measure is needed to capture the true lighting pattern influencing driver vision at night.
PMID: 30971143 [PubMed - as supplied by publisher]

Source: Traffic Injury Prevention - April 10, 2019 Category: Accident Prevention Authors: Yang R, Wang Z, Lin PS, Li X, Chen Y, Hsu PP, Henry A Tags: Traffic Inj Prev Source Type: research