Sign Retroreflectivity: Fiscal Impact of Proposed Minimum Retroreflectivity Values on Local Governments in Indiana and Investigation of the Accuracy of Nighttime Inspections

To remain effective, traffic signs need to be clearly legible to all motorists. Their retroreflectivity is an important factor in their legibility because it directly correlates to the visual luminance of the sign. Recently, the Federal Highway Administration (FHWA) has proposed a set of minimum retroreflectivity values to which all signs shall conform. The purpose of this study was two fold: to investigate the fiscal impact of these proposed minimums on roadways managed by counties, cities, and towns within the State of Indiana and to compare the accuracy of a simple nighttime inspection method to the more labor intensive measured retroreflectivity method. Estimates performed on the collected data suggest that the fiscal impact of these proposed standards will be felt greatest by cities with an estimated statewide total cost of $6.6 million. The added statewide fiscal burden on counties and towns was estimated to be $4.9 million and $2.7 million, respectively, for a combined total impact of $14.2 million. The analysis also showed that the nighttime inspection method, with minimally trained personnel, provided an 88 percent level of accuracy and was completed in approximately half of the time that it took to directly measure retroreflectivity. The proposed six year phase in period, in conjunction with a structured sign inspection and replacement program that incorporates a nighttime inspection method should help to reduce the immediate fiscal impact felt by local governments within the State of Indiana.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Kilgour, Matthew David
  • White, Joshua Daniel
  • Bullock, Darcy M
• Conference:
  • Transportation Research Board 86th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2007-1-21 to 2007-1-25
• Date: 2007

Language

• English

Media Info

• Media Type: CD-ROM
• Features: Figures; References; Tables;
• Pagination: 18p
• Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

• TRT Terms: Benefit cost analysis; Illuminated traffic signs; Inspection; Night visibility; Retroreflectivity; Standards; Traffic signs; Transportation policy
• Geographic Terms: Indiana
• Subject Areas: Highways; Policy; Safety and Human Factors; I85: Safety Devices used in Transport Infrastructure;

Filing Info

• Accession Number: 01054577
• Record Type: Publication
• Report/Paper Numbers: 07-0387
• Files: BTRIS, TRIS, TRB
• Created Date: Feb 8 2007 4:57PM