Performance Evaluation of Retroreflective Traffic Signs

Today, retroreflective sign sheeting is mostly cataloged using ASTM D4956. A new specification by AASHTO (M268) is also being used in some state departments of transportation (DOTs). Both of these specifications catalog products using the coefficient of retroreflection (also known as retroreflectivity) as the key performance indicator. While retroreflectivity is a metric that can be easily measured, at the current specification geometries, the retroreflectivity by itself is not always a good indicator of the performance of the material as seen at night from the perspective of a driver. Over the past few years, there have been various attempts to develop other criteria to catalog sign sheeting materials. This paper summarizes the latest methodology for evaluation of sign sheeting materials. The methodology was developed within the scope of the Commission Internationale de l’Eclairage (CIE) Technical Committee 4-40. The TC4-40 report is currently being balloted by member countries. The method described provides a way to evaluate the nighttime performance of traffic signs as they are used and with a metric of luminance rather than the coefficient of retroreflection. The report is supplemented with a computation tool (small computer program) that can be used to quickly assess sign sheeting performance using the methodology described.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AND40 Visibility.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Carlson, Paul J
• Conference:
  • Transportation Research Board 94th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2015-1-11 to 2015-1-15
• Date: 2015

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 11p
• Monograph Title: TRB 94th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Computer programs; Evaluation; Luminance; Methodology; Night visibility; Retroreflectivity; Sign sheeting; Traffic signs
• Identifier Terms: International Commission on Illumination (CIE)
• Subject Areas: Highways; Materials; Operations and Traffic Management; I30: Materials; I73: Traffic Control;

Filing Info

• Accession Number: 01553737
• Record Type: Publication
• Report/Paper Numbers: 15-2963
• Files: TRIS, TRB, ATRI
• Created Date: Feb 21 2015 4:38PM