Overhead guide sign retroreflectivity and illumination.

Details

• Creators:
  Obeidat, Mohammed ; Rys, Malgorzata ; Russell, Eugene R.
• Corporate Creators:
  Kansas State University. Transportation Center
• Subject/TRT Terms:
  • Overhead traffic signs
  • Retroreflectivity
  • Visibility
  • Energy conservation
  • Costs
  • Lighting
  • Surveys
  • State departments of transportation
  • Field tests
  • Laboratory tests
  More +
• Publication/ Report Number:
  K-TRAN: KSU-11-6
• Resource Type:
  Tech Report
• Geographical Coverage:
  Kansas
• Corporate Publisher:
  Kansas. Dept. of Transportation
• Abstract:
  Roadway guide sign visibility during darkness is fundamental to driver safety, especially elderly drivers. Guide ; sign visibility can be improved by external sign illumination or the use of retroreflective sheeting on signs. Because ; energy conservation is essential in the midst of a worldwide energy crisis, various Departments of Transportation have ; investigated usage of energy-efficient lighting technology with overhead guide signs. ; This report presents results of a survey related to overhead sign lighting usability by states, a laboratory ; experiment to compare the light distribution of five light sources used to illuminate overhead guide sign by several ; states, a cost analysis for the tested light sources, a field experiment to compare the visibility of three retroreflective ; sheeting used by states, a cost analysis for the tested retroreflective guide signs, and an analysis by determining the ; most cost-effective method of increasing overhead guide sign visibility to drivers during nighttime. ; A laboratory experiment was conducted to compare the light distribution of three conventional light sources: ; Metal Halide, Mercury Vapor, and High Pressure Sodium, and two new generation light sources: Induction lighting, ; and Light Emitting Diode. Combining two decision criteria, the light distribution and the cost, resulted in finding the ; Induction lighting to be the recommended light source for those states that want to continue illuminating their ; overhead guide signs. A field experiment was conducted to compare three types of sign sheeting, Engineering Grade ; (type I), Diamond Grade (type XI), and High Intensity (type IV), in order to determine the sign sheeting material that ; best improves sign visibility. Combining the decision criteria to compare these three retroreflective sheeting, the ; visibility and the cost, High Intensity (type IV) is the recommended sign to be used by DOTs, followed by Diamond ; Grade (type XI). ; In comparing the best options used to increase sign’s visibility, sign illumination and sign retroreflectivity, it is ; found that using retroreflective sheeting is more cost effective than sign illuminating.
  More +
• Format:
  PDF
• Funding:
  C1889
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/28555/dot_28555_DS1.pdf
• File Type:
  [PDF - 1.89 MB]
• Collection(s):
  University Transportation Centers ; US Transportation Collection
• Main Document Checksum:
  urn:sha256:1a77d369283d04d9d65ef6142d618be35fc5442280e039ba1b9c1d5d5e61c4b0