LED streetlighting has become a mainstay in urban planning. In the UK, there are approximately 3.9 million LED lanterns, representing almost 55% of all street lights, according to the Chartered Institution of Highways & Transportation (CIHT).
With high energy efficiency and long lifespan, LEDs are steadily replacing older, less efficient technologies like SON and SOX sodium discharge lamps. While LED streetlights provide clear benefits, their impact on community wellbeing, including on sleep, mental health, and safety, requires a more nuanced consideration.
Developing an LED streetlight strategy that meets all aspects of community lighting needs, while minimising light pollution and its effects on people and the natural environment, is crucial.
LED streetlights offer several key advantages over traditional lighting technologies:
However, in areas where LED streetlights are excessively bright or poorly positioned, lighting can have unintended consequences on community health and local wildlife.
Some LED streetlights emit high levels of blue light. Research shows that exposure to blue light, particularly at night, can interfere with circadian rhythms — the body's internal clock that regulates sleep and wake cycles. Blue light at night suppresses melatonin, the hormone responsible for sleep, making it harder to fall asleep and stay asleep.
Excessively bright streetlighting also contributes to light pollution, impacting both humans and wildlife. Glare from LED lights can create visual discomfort, affecting drivers’ and pedestrians’ ability to adjust to darkness and navigate safely. Light pollution can also obscure the night sky, diminishing the natural beauty of the stars and disrupting nocturnal ecosystems.
LED streetlights are primarily installed to enhance nighttime visibility. According to the UK's College of Policing, well-designed urban street lighting can reduce night-time crime by up to 20%. This does not necessarily mean the use of lighting all through the night. Studies suggest that part-night lighting (PNL), where streetlights are dimmed or turned off between midnight and 5am, can help reduce certain crimes, such as vehicle-related offences.
Furthermore, communities differ in their preferences. While some residents appreciate the added visibility and security, others find the lighting intrusive and disruptive to their quality of life.
There are a variety of ways to approach LED streetlighting to strike a balance between safety and community wellbeing:
While LED streetlighting provides significant benefits in terms of energy efficiency, cost savings, and enhanced visibility, it is essential to strike a balance between brightness and community wellbeing.
By considering the health impacts of excessive brightness and taking steps to mitigate light pollution, our villages, towns, and cities can be safer, healthier, and better environments for residents and local wildlife.