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:
  Collisions Illuminance Intersections Isolated Intersections Lighting Luminance Rural Intersections Rural Transit Street Lighting
• 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.
  
  
• Format:
  PDF
• Funding:
  2013012 ; (c) 99008 (wo) 39
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:1bce6d5cca68a7b8268f0d83dc5e366e97c32c1f5a921af92a1890ea1091b327
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/32165/dot_32165_DS1.pdf
• File Type:
  [PDF - 1.12 MB ]