City Street Lights Information

City street lights have become more efficient over the years.

Whether used for safety, clarity or security, city street lights reduce the number of traffic accidents during the nighttime hours, reduce the severity of the accidents that do occur, and reduce the risk of vehicle versus pedestrian accidents.

Uses

Street lights fall into three categories: beacons, which produce enough light for drivers to see but don't illuminate large areas; roadway lighting, which shines brightly in potentially hazardous areas, like exit ramps or busy intersections; and security lighting, which illuminates large areas and is used commonly for sidewalk areas of large cities.

Operation

Most street lights use a "dawn-to-dusk" function, using photocells that detect the amount of light outside. At night or under overcast skies, the photocells allow electricity through, lighting the bulb. When the light reaches a predetermined level, the photocells stop the flow of electricity.

Regulation

City street lights are regulated by each city, based upon its own needs.

Disadvantages

Bright lights in an otherwise dark area create problems with natural night vision abilities. Because eyes take longer to adjust to the dark after exposure to bright lights, reaction time may be compromised. In addition, excessive city street lighting creates light pollution, making the stars less visible.

References

• Dark Sky Society: Development of Outdoor Lighting Regulations
• The Royal Society for the Prevention of Accidents: Street Lighting and Road Safety
• Trip Atlas: Street Light