Our solutions for road and street help customers meet their goals relating to innovation and infrastructure, sustainable cities and communities, responsible consumption, protecting the planet as well as peace and justice.

Our customers include governments, councils, municipalities, developers and consultants.

With the right products, technologies and controls, we can ensure their interests and goals are met. Some of these include NightTune technology, Variable Light Distribution and UrbaSens.

Our knowledgeable and experienced team can advise which luminaires and technology provide the best solution based on the individual requirements of that customer.

Watch our 'Protecting Cumbria's Dark Skies' video to see how Cumbria County Council is helping to protect its dark skies while at the same time, enhancing peoples' perception of safety in urban spaces and bringing communities together

It’s important that our lighting designs and products balance the safety requirements of people, protects local biodiversity and respects the night sky. Energy efficiency, cutting-edge design and smart control make sure light is only used when and where it is needed. Quality lighting from luminaires with well-designed optics and good beam control helps prevent spill light, protecting the environment and nature.

Unwanted light that spills onto unrelated areas is known as obtrusive light. It reduces the efficiency of lighting installations as light is being wasted. It also causes inconvenience or damage in the surrounding areas.

ULR: the upward light ratio.

This is the proportion of light that is emitted at or above the horizontal when a luminaire is mounted in its installed position. This data gives the proportion of light directly contributing to sky glow. If you need this calculation to be made for your lighting installation, do get in touch and we can help.

There are three main forms of obtrusive light:

  • Spill light, which is light emitted by a lighting installation that falls outside the boundaries of the area for which the lighting is designed.
  • Sky glow, which is light that contributes to the brightening of the night sky.
  • Light trespass, is when light spills onto surrounding properties causing annoyance, distraction, or discomfort. An additional form of light trespass is when the direct view of bright luminaires causes the same issues.


  1. Control - Excessive light is not only a waste of energy, but it can be a source of pollution leading to a range of negative effects on the natural environment and ecosystem. Variable Light Distribution programming can significantly reduce the risk of pollution. Control systems adjust light levels based on time of day or night and detect the presence of people or vehicles. Thorn luminaires are equipped with the latest control technologies using NEMA and Zhaga compliant components, meeting Zhaga-D4i certification, or other advanced controls, to reduce light pollution and save energy.
  2. Shield - Thorn’s optical system is designed for ULOR at 0 % so that light is not emitted upwards into the sky. Our products can also have an additional internal louvre that ensures a perfect cut-off. This feature minimises spill light and avoids obtrusive light.
  3. Colour Temperature - Warm colour temperatures (up to 3000K) minimise disruption to the nocturnal ecosystem and create a comfortable atmosphere. Carat has been equipped with our latest NightTune and Variable Light Distribution technologies, designed to create the perfect balance for lighting the night.

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