The illumination of a roadway and/or parking facility by a fixed source.
- The Illuminating Engineering Society of North America (IESNA), Roadway Lighting
- PennDOT Design Manual Part II: Highway Design: Chapter 5 — Lighting
Parking and other site facilities
Lighting may improve the safety of a highway or street and the ease and comfort of operation. Statistics indicate that the night time accident rate is higher than that during daylight hours, which to a large degree, may be attributed to impaired visibility. Evidence shows that in urban and suburban areas, where there are concentrations of pedestrians and roadside intersectional interferences, fixed source lighting tends to reduce accidents. The general consensus is that lighting of rural highways seldom is justified except on certain critical portions, such as intersections and interchanges, and areas where roadside interference is a factor. (AASHTO)
Warrants are factual evidence compiled for the purpose of justifying the installation of roadway lighting. Warrants should be based on conditions relating to the need for roadway lighting and the benefits it may provide. Factors such as traffic volume, speed, road use at night, night accident rate, road geometrics, and general night visibility are important considerations in determining the minimum conditions justifying lighting. (ITE)
Lighting that supports pedestrian access to and from bus stops, as well as visibility for waiting bus passengers is highly encouraged. When possible, SEPTA places bus stops in locations where lighting is provided. Lighting should be considered as part of implementing SEPTA's Bus Stop Design Guidelines.
Attractive and appropriately sized street lighting fixtures are an important design element to consider during land development review. Where light pollution is a concern, the minimum amount of lighting needed for safety should be provided. In suburban areas with a higher density or level of traffic, an increased level of lighting may be appropriate for safety considerations. More energy efficient light fixtures are being developed every day. LED lighting technologies have advanced considerably in recent years offering significant energy cost savings with the long term operation of these fixture types versus traditional bulbs.
- For roadway lighting, follow the recommendations of PennDOT Design Manual Part II: Highway Design: Chapter 5 — Lighting; and, the Illuminating Engineering Society of North America (IESNA), Roadway Lighting.
- For parking facility and other site lighting, follow the guidance contained in the Illuminating Engineering Society of North America (IESNA) Lighting Handbook.
- Municipalities should ensure their lighting ordinance addresses the following criteria: illumination levels, lighting fixture design, control of nuisance and disabling glare, installation, energy efficiency, and light pollution/trespass.
- Site lighting should be directed inwardly from the periphery of a site to minimize the off-site impacts of lighting such as reducing glare and visual impacts on the adjacent roadways and adjoining land uses while providing for lighting that is sufficient for the safe use of a property. All lighting shall be aimed, located, designed, fitted and maintained so as not to present a hazard to drivers or pedestrians by impairing their ability to safely traverse and so as not to create a nuisance by projecting or reflecting objectionable light onto adjacent properties, past the object being illuminated, skyward, or onto a public roadway.
- Municipalities should require that a lighting plan be submitted with the preliminary development plan applications.
- The design of light fixtures should be consistent with the character of the area, the specific lighting application, and should otherwise comply with the Uniform Construction Code.
- Energy-efficient lighting design and operation should be used wherever possible.
- All exterior lighting shall meet IESNA full-cutoff criteria.
For more information regarding the effects of light pollution, please refer to the International Dark-Sky Association website.