Illumination and Visibility of Workers in Nighttime Highway Work ZonesAuthor/Presenter: Jafarnejad, Ali; Gambatese, John A.; Nnaji, Chukwuma
Much of the construction work that occurs on high-speed roadways takes place at night to minimize impacts on drivers. Performing work at night exposes workers to hazards that are not present during the daytime such as driver drowsiness, alcohol use, and reduction in visibility. Illuminating the area where work is taking place can provide sufficient lighting for the workers to see their work and help them to be more visible. Depending on various factors such as the amount of light needed and the nature of work operation, different lighting equipment is used for illumination. Mobile lights attached to the construction equipment, portable lights, and personal lights worn by workers are examples that can be used to provide the necessary lighting. The authors performed a survey of current lighting systems and practices in preservation project work zones across the U.S. The impact of two lighting systems including the light tower and balloon light on visibility of the workers was evaluated. The authors examined the visibility of workers at different distances, various locations in regards to the light and with different high visibility apparel. The results of the survey showed that a portable light tower and balloon lights are the most commonly-used types of lighting system in construction work zones. Moreover, workers feel safer when using additional personal light equipment such as a flashlight. The location of the worker on the roadway relative to the light location is a significant factor in the visibility of the worker. Selected lighting strategies are provided to be considered in designing nighttime work zones to improve the visibility of workers and increase safety in highway work zone construction.