01592868

Component

The regular auditing of installed roadway lighting performance is essential to ensure that in-situ light levels are within design specifications despite effects of lamp deterioration and/or changes in roadway functional class. However, existing guidelines for measuring roadway lighting performance are tedious and often impractical for transportation agencies and municipalities, who are already faced with time and resource constraints. This paper develops a method for calibrating a digital single lens reflex camera for rapid assessment of illumination levels at roadway intersections. The method uses an image analysis approach to extract pixel information in a digital image and link it to the actual scene luminance. It uses high precision light meters to perform an initial calibration of the digital camera that has proven to be stable over long periods. The method is tested with field data and the results show that average scene luminance derived from this method differs less than 4 percent from the average observed scene luminance captured by high precision luminance meters involving a rigorous field measurement methodology. The methodology developed in this study offers transportation agencies and municipalities a rapid, inexpensive, and efficient method to audit the adequacy of roadway illumination.

This paper was sponsored by TRB committee AND40 Standing Committee on Visibility.

01584066

16-5723

English

18p

2016

Transportation Research Board 95th Annual Meeting

Web

Figures; Photos; References (33) ; Tables

Digital cameras; Field tests; Image analysis; Intersections; Lighting; Street lighting; Structural health monitoring

Highways; Operations and Traffic Management; Safety and Human Factors

Transportation Research Board Annual Meeting 2016 Paper #16-5723

TRIS, TRB, ATRI

Jan 12 2016 6:31PM