Lighting provides one of the most effective night-time intersection safety countermeasures. However, lighting is also one of the main contributors to intersection maintenance and operation costs. For a public transportation agency with jurisdiction over many intersections, the system-wide lighting costs can significantly deplete already limited funds for other important maintenance projects. A sound framework for conducting benefit-to-cost trade-off analysis would be beneficial to transportation agencies. Unfortunately, published works on the benefit-to-cost analysis are few and mostly dated. This paper outlines a detailed framework for conducting benefit-to-cost analysis for rural intersection lighting. The framework uses intersection lighting simulation models to generate annualized operating and maintenance cost data for different lighting levels. The intersection lighting models were developed with DIALux® professional lighting software. This study used the framework to conduct a case study of rural conventional three-leg and four-leg intersections with at least an annual average daily traffic (AADT) of 500 from Georgia. Based on the available Georgia case study data, this paper finds that for rural intersection locations that require no electrification, basically any illumination level, including those less than the recommended minimum of 8 lux, is likely to be cost-effective for any entering AADT. However, locations that require electrification need to be evaluated based on the overall costs, entering AADT, existing crash rate, and a target benefit-to-cost ratio that signifies the level of cost-effectiveness required by the state Department of Transport (DOT). Consequently, a companion spreadsheet benefit-to-cost model has been developed to facilitate the cost-effectiveness analysis at any rural uncontrolled or stop-controlled intersection.

The regular auditing of installed roadway lighting performance is essential in ensuring that in situ light levels are within design specifications despite the effects of lamp deterioration or changes in roadway functional class. However, existing guidelines for measuring roadway lighting performance are tedious and often impractical for transportation agencies and municipalities, which are already faced with time and resource constraints. A method for calibrating a digital single lens reflex camera for rapid assessment of illumination levels at roadway intersections is developed in this paper. The method uses an image analysis approach to extract pixel information in a digital image and link it to the scene luminance. It uses high-precision light meters to perform an initial calibration of the digital camera that has proved to be stable over long periods. The method was tested with field data, and the results indicate that average scene luminance derived from this method differs by less than 4% 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 for auditing the adequacy of roadway illumination.