Illumination is a roadside obstacle that requires appropriate safety treatment. All illumination features, such as poles and foundations, must be checked against the appropriate clear zone requirements. If the illumination feature is deemed crashworthy by the Department, it can be placed within the clear zone without additional roadside safety hardware for protection. Safety treatment may include barrier, metal beam guard fence, cable barrier, or other crashworthy roadside safety hardware. While locating non-breakaway illumination poles outside of the clear zone meets minimum requirements, where feasible, locations that are as near to the ROW as possible are desirable; for example, beyond the front-slope and outside the run-out area of relatively steep slopes. Refer to the applicable for specific application of illumination features.

Adequate access must be provided within the State ROW for department-maintained illumination systems. Elements such as luminaires, poles, ground boxes, and electric service must be accessible by maintenance vehicles and maintenance personnel. Where practical, it is desirable for the illumination system to be accessed without disrupting existing traffic.

Illumination pole locations must be reviewed to ensure they do not adversely impact hydraulic operation of roadside ditches or roadside maintenance operations.

Existing utilities and subsurface features such as culverts, storm sewer, waterlines, and gas lines can also influence the location of illumination poles. Foundations must be verified with subsurface data to ensure clearance requirements are met.

Lighting systems near special facilities will have specific horizontal and vertical clearance requirements. Special facilities may include railroad tracks, airports, helicopter landing pads, and overhead electric lines.

Illumination should complement the context classification of the facility. The presence of off-site glare or skyglow (i.e, light pollution) near residential areas or nature preserves should be taken into consideration. A photometric analysis should be performed to evaluate these impacts and address community concerns. Local ordinances and aesthetic requirements may dictate the type and design of lighting to be installed, such as decorative poles or luminaires.

Being able to adequately see the road ahead to observe conflicting traffic and the behavior of other highway users, including where bicycles and pedestrians are present, is integral to driving. Illumination significantly improves the visibility of the roadway, increases sight distance, and makes roadside obstacles more noticeable and therefore more avoidable.

In addition to traffic safety, adequate lighting provides benefits in terms of personal security. Roadway illumination often serves the purpose of safeguarding personal safety for pedestrians, bicyclists, and transit users. Darkness can reduce personal security. Walking, bicycling, or commercial activities may become uncomfortable or unsafe if adequate illumination is not provided. Therefore, ensuring that the lighting provides acceptable levels of illumination can be a great benefit to all users of the roadway environment.