Lighting levels for isolated intersections : leading to safety improvements : final report.

Details

• Creators:
  Edwards, Christopher J.
• Corporate Creators:
  University of Minnesota. Department of Mechanical Engineering. HumanFIRST Program
• Corporate Contributors:
  Minnesota. Dept. of Transportation. Research Services & Library
• Subject/TRT Terms:
  • Street lighting
  • Intersections
  • Isolated intersections
  • Lighting
  • Luminance
  • Collisions
  • Rural transit
  • Illuminance
  • rural intersections
• Publication/ Report Number:
  MN/RC 2015-05
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Minnesota
• Edition:
  Final report
• Corporate Publisher:
  Minnesota. Dept. of Transportation. Research Services & Library
• Abstract:
  A number of studies have linked the benefits of roadway lighting to a reduction in crash rates at night for a variety ; of roadway types including rural intersections. Assessing the effectiveness of intersection lighting has primarily ; relied upon crash database modeling comparing lighted intersections to unlighted intersections. The current ; research effort gathered similar metrics for comparison but also measured the amount of lighting within isolated ; rural intersections. Sixty-three intersection locations were chosen for lighting measurement from six different ; counties within Minnesota. A vehicle mounted illuminance meter data collection system was used to collect data at ; each intersection. The data collection system utilized five separate illuminance meters and captured horizontal ; illuminance while driving through all 63 intersection locations. Following data collection, a series of negative ; binomial regression models were used to assess the horizontal lighting level in conjunction with the nighttime crash ; ratio, intersection configuration type, and proximity of an intersection to a curve in the roadway. The first model ; used data from the lighted an unlighted intersections. The results showed that across all intersections, an increase in ; the average horizontal illuminance (3.91 lux) by 1-lux (~0.09 fc) reduced nighttime crash rates by 9%. A second ; model used only lighted intersection data and showed an increase in 1-lux from average (6.41 lux) reduced crashes ; by 20%. A third and final model used unlighted intersections only. A 1-lux increase from average (0.20 lux) or ; increasing illuminance to lighted levels (as defined by the modeling), reduced nighttime crash ratios by 94%. ; Intersection configuration and proximity to curves also affected the nighttime crash ratios. The results of this effort ; are discussed in terms the impact of horizontal illuminance on crash rates. Additional items discussed include ; thresholds for minimum and maximum lighting levels and future research investigating and validating these efforts.
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• Format:
  PDF
• Funding:
  2013012 ; (c) 99008 (wo) 39
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/32165/dot_32165_DS1.pdf
• File Type:
  [PDF - 1.12 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:1bce6d5cca68a7b8268f0d83dc5e366e97c32c1f5a921af92a1890ea1091b327