streetlights

Streetlights are outdoor lighting fixtures installed along streets, roads, and public spaces to provide illumination for pedestrians, cyclists, and motorists. They extend usable hours after dusk, improve visibility, and support safety, navigation, and nighttime urban activity.

Most streetlights suspend luminaires from poles or brackets. Common lamp technologies include LED, high-pressure sodium, metal halide, and, in older installations, low-pressure sodium. In recent decades LEDs have become dominant due to energy efficiency, long life, and better color rendering; some systems remain solar-powered or hybrid.

Design and placement consider pole height, fixture spacing, and the distribution pattern of light to achieve uniform illumination while minimizing glare and light trespass. Shielded designs and appropriate color temperature help reduce skyglow and protect adjacent properties and wildlife.

Operations rely on energy management and controls such as photocells, timers, and dimming. Modern networks may incorporate smart controls and remote monitoring to adjust intensity based on time, weather, or traffic, reducing energy use and maintenance costs.

The widespread use of street lighting supports safety, traffic management, and economic activity at night, but it also raises concerns about light pollution and ecological impact. Life-cycle costs include energy, maintenance, and eventual replacement of luminaires and electrical gear.

Standards and guidelines from bodies such as the Illuminating Engineering Society and regional regulatory agencies influence luminance, glare control, and energy targets. Typical LED luminaires last 15 to 25 years with periodic maintenance to replace components and ensure consistent performance.