For new or refurbished public lighting to be truly efficient, the right luminaire and optics must be selected. A poor choice can require unnecessarily higher power, illuminating areas that do not need light.

Choose luminaires to suit their location. Road lighting, for example, uses a wide light distribution, whereas squares need an even distribution. The luminaires may look identical, but using the wrong type is likely to result in failure to meet the standard.

LED sources are available across a wide range of colour temperatures. Most current luminaires use cool white light (5,300 K and above), which is suitable mainly for applications such as pedestrian crossings, large open areas or architectural features. Neutral white (3,300–5,300 K) and warm white (3,300 K and below) are more suitable for town centres, squares, pedestrian zones and residential areas.

Only a lighting calculation can establish whether illumination is sufficient without being excessive. Without this verification, roads or sections of them may be overlit, unevenly lit, insufficiently lit or fitted with unsuitable luminaires. There is no universal solution, so a project-specific design is always necessary.

Public lighting should provide both sufficient light and uniformity. Trying to save electricity by switching off selected lighting points creates alternating stretches of light and darkness, one of the most dangerous situations. The human eye cannot adapt to these changes at driving speed, making it easy for a driver to miss a pedestrian or another obstacle.