Roadway Lighting Shows Safety Benefits at Rural Intersections

Abstract

Intersection-related crashes account for approximately 31% of fatal crashes in Minnesota and roughly 37% of those occurred at night, dusk, or dawn. Nationally, intersection-related fatal crashes accounted for 21% of all fatal crashes and 40% of those crashes occurred during dark, dusk, or dawn light conditions while only 25–33% of the vehicle miles traveled occur at night. Furthermore, Minnesota experienced 70% of its fatal crashes in rural areas, as compared to 58% nationally. As a result, rural intersections at night are at higher risk for fatal crashes than other locations in Minnesota. This research was part of Research Rep. No. MN/RC-2006-35, “Safety impacts of street lighting at isolated rural intersections—Part II.” This research evaluated the effectiveness of roadway lighting in reducing nighttime crashes at isolated rural intersections. A before-and-after study was used to evaluate the impact of lighting at 33 intersections with 3 years of before data and 3 years of after data. A Poisson regression model evaluated the change in the expected number of crashes after installation of lighting. Crash rate was calculated using this information and used to compare day versus night since volumes are expected to differ. Results indicated that the night crash rate was 37% lower after lighting was installed and was statistically significant. The change in daytime crash rate from the before to after period was 4% but was not statistically significant indicating that there was no overall change in crash rate during the analysis period due to other factors.