High visibility reflective sign sheeting materials: field and computational evaluations of visual performance
Abstract
Highway signs provide important information to drivers to assist in navigation, to identify potentially hazardous roadway locations, and to remind drivers of safe operating practices. Ensuring that signs have sufficient visibility to the driving public is a key undertaking by transportation agencies. In order to assist in evaluating and comparing different materials for photometric and visual performance, the present study was undertaken to assess the utility of specifying sign sheeting performance in terms of visual performance. As part of this effort, a practical methodology for conducting field measurements of sign luminance along roadways was developed. In addition to describing the methods for an approach to visual performance based specifications, a spreadsheet tool for calculating minimum sign luminance and visibility from different sign sheeting materials was also developed.
First published online 20 October 2016
Keyword : retroreflective signs, visual performance, sign legibility, sheeting materials
This work is licensed under a Creative Commons Attribution 4.0 International License.
References
Bullough, J. D.; Radetsky, L. C. 2014. Roadway lighting, relative visual performance and safety, in Proceedings of the Illuminating Engineering Society Annual Conference 2014, 2–4 November 2014, Pittsburgh, Pennsylvania, US, 203–207.
Bullough, J. D.; Skinner, N. P.; O’Rourke, C. P. 2010. Legibility of urban highway traffic signs using new retroreflective materials, Transport 25(3): 229–236. http://doi.org/10.3846/transport.2010.28
Carlson, P.; Miles, J.; Park, E. S.; Young, S.; Chrysler, S.; Clark, J. 2010. Development of a Model Performance-Based Sign Sheeting Specification Based on the Evaluation of Nighttime Traffic Signs Using Legibility and Eye-Tracker Data. Report No FHWA/TX-10/0-5235-1-VOL1. Texas Transportation Institute, Texas A&M University, US. 190 p. Available from Internet: http://tti.tamu.edu/documents/0-5235-1-VOL1.pdf
Goodspeed, C.; Rea, M. S. 1999. The significance of surround conditions for roadway signs, Journal of the Illuminating Engineering Society 28(1): 164–173. http://doi.org/10.1080/00994480.1999.10748263
NYSDOT. 2016. Sign Calculator. New York State Department of Transportation (NYSDOT). Available from Internet: http://www.dot.ny.gov/divisions/engineering/technical-services/trans-r-and-d-repository/NYSDOT-C-07-03-SignCalculator.xls
Ré, J. M.; Miles, J.; Carlson, P. J. 2011. Analysis of in-service traffic sign retroreflectivity and deterioration rates in Texas, Transportation Research Record: Journal of the Transportation Research Board 2258: 88–94. http://doi.org/10.3141/2258-11
Rea, M. S. 1989. Visibility criteria and application techniques for roadway lighting, Transportation Research Record: Journal of the Transportation Research Board 1247: 12–16.
Rea, M. S.; Ouellette, M. J. 1991. Relative visual performance: a basis for application, Lighting Research and Technology 23(3): 133–144. http://doi.org/10.1177/096032719102300301
Schnell, T.; Yekhshatyan, L.; Daiker, R. 2009. Effect of luminance and text size on information acquisition time from traffic signs, Transportation Research Record: Journal of the Transportation Research Board 2122: 52–62. http://doi.org/10.3141/2122-07
Schoettle, B.; Sivak, M.; Flannagan, M. J.; Kosmatka, W. J. 2004. A Market-Weighted Description of Low-Beam Headlighting Patterns in the U.S.: 2004. Report No. UMTRI-2004-23. University of Michigan, US. 18 p. Available from Internet: https://deepblue.lib.umich.edu/bitstream/handle/2027.42/55198/UMTRI-2004-23.pdf
Skinner, N. P.; Bullough, J. D.; Smith, A. M. 2010. Survey of the present state of headlamp aim, in TRB 89th Annual Meeting Compendium of Papers DVD, 10–14 January 2010, Washington, DC.