As the nation’s highways and roadways age and continue to see increases in traffic, concerns for keeping up with the growing demand for a safe transportation infrastructure have increased as well. Studies continue to be published showing the effects that age and traffic volumes are having on existing roadways and bridges and recommendations continually point towards refurbishing existing roads along with constructing new ones to help alleviate the congestion and hazards that are increasing in volume. Difficulties in accomplishing this construction and refurbishment are already expensive and time consuming, and concerns with construction further adding to congestion problems have tended to compound the issue. In response to these concerns the choice to perform this work at night has increased in popularity and city and state governments are moving in many areas to further increase the scope of the projects performed outside of traditional daylight work hours.

Shifting construction projects to nighttime hours has allowed contractors to avoid many of the problems associated with performing large scale roadwork. Traffic volumes are greatly reduced during the late evening and early morning hours and the difficulties encountered in managing traffic flow are as a result also lessened. Although some contention exists, some studies have suggested that the safety of the workers involved in these projects has been improved by shifting operations to periods of lowered traffic volumes. Costs continue to be a large factor in enacting these projects and some contractors have been reluctant to engage in nighttime projects because of the possibility of increased costs that are associated. Often cited in these extra costs is the equipment necessary to conduct operations safely and efficiently in the dark. Traffic control and visibility are two of the main concerns with performing nighttime roadwork and both present challenges that must be addressed if projects are to run smoothly.

Although traffic volume is reduced during the off peak evening hours reducing the interaction between work crews and the public, it is still a major problem. Although traffic volume has decreased, the reduced visibility brought about by darkness and the presence of workers and equipment in the roadway combine to create serious safety hazards. Because of this it is critical that workers be clothed in reflective gear, traffic control devices be highly visible and functioning, and lighting of the work area be properly chosen and placed. Lighting in the work area is probably the single best tool contractors have to ensure the safety of their workers and the efficiency of the project. Well lit job sites are easily visible from long distances, and workers are much more efficient when they can easily observe all of the work that is being performed.

Job site lighting tends to be most effective when the lighting used mimics the color spectrum of natural light, and studies show that worker fatigue and sleep cycle disruption is lessened somewhat when quality lighting is provided. In a report published by the New York State Department of Transportation, they found that workers reported several detrimental effects from working a late evening shift. Among these effects were cited disruption of the sleep cycle and difficulties in adjusting to an altered work schedule. Another report issued by the U.S. Dept. Of Energy notes that worker productivity tends to improve with exposure to natural light. Additionally, workers utilizing natural spectrum lighting also showed fewer problems with the fatigue caused by working in poorly illuminated conditions.  The obvious inference is that job site lighting should mimic natural light if possible and operate within the same spectrum. To that end, lighting equipment used on job sites should be considered with an overall approach rather than one geared towards simple costs and savings. Although an initial outlay may be smaller for a lighting system that sacrifices light quality for brightness, the resultant improvements in worker productivity and efficiency that may be had with a more natural light will not be realized.

Commonly used lights in construction like Quartz Halogens tend to produce a very unnatural yellowish orange light. Along with High Pressure Sodium lamps, their light spectrum is heavily shifted towards the red. The results are not only an unnatural quality of light, but light that does not present the true colors and detail of objects that are illuminated with it. In operations that involve close work, a true color representation is very important in how it relates to the efficiency and productivity of the work being performed. Metal Halide lamps on the other hand produce a high quality light beam that is much closer to the spectrum found with natural light. The light created with Metal Halide tends to be shifted more towards the blue end of the light spectrum with a much more balanced ratio of light from red to blue overall. Because of this, the light produced by Metal Halide lamps is visibly whiter and objects illuminated by it appear brighter and sharper in detail.

Metal Halide lamps are readily available for use in the construction industry and several companies like Magnalight offer several designs and types to choose from. For road construction projects where large areas must be illuminated, light towers like the WAL-C-1XM Portable Light Tower are a good fit both in power and light quality. In the WAL-C-1XM a one thousand watt Metal Halide lamp is used to produce 110,000 lumens of bright full spectrum light. Capable of illuminating 23,000 square feet, the light tower can be extended from 7 feet to 12 feet high helping to cover a large area while allowing adjustment to help reduce the glare that lights positioned too low can often cause. Correctly positioned, this type of Metal Halide lighting system can provide great benefit to both the workers on the job site as well as the contractors who oversee them.

The natural spectrum of light produced by Metal Halide lamps is excellent for close work like cutting grades or assembling wiring and workers will not find themselves squinting and becoming excessively fatigued from trying to focus on a task under unnatural lighting conditions. Equipment operators and the public benefit as well since objects are much more clearly defined and rendered more naturally by the wide spectrum light produced by Metal Halide lamps. Safety is maintained as well as workers performing in the midst of traffic will be better illuminated and visible to drivers as they pass through and by the construction zone.

The end results of choosing to work with lighting that produces a powerful source of natural illumination are improved productivity and efficiency while ensuring a high level of safety. While any nighttime work performed is going to force an added expense in the form of lighting equipment, choosing that lighting wisely can result in a net benefit to both the worker, and the businesses that employ them.