Shining a light on road safety

Scientists at the National Physical Laboratory (NPL) are hoping to make driving safer during the most dangerous part of the day for motorists - twilight

Twilight - defined as the natural stage between light and dark - does not just occur as day turns to night. Twilight conditions can appear through environmental changes including foggy and smoky conditions and although only a quarter of journeys take place at this time, 40% of all road accidents happen at twilight.

According to the NPL this is because whilst we know lots about how the eye performs in bright light and low light, we know little about what happens as we transition from one to the other.

Most public lighting and vehicle headlights are built to deliver optimum illumination in darkness, but most headlights cause perpetual twilight conditions making it difficult for drivers to see. Because of this NPL is forming part of a team developing international standards for public lights such as street lamps and car headlights. By measuring the way our eyes work when the light is poor, NPL hope to build the first international standards for public lighting in twilight conditions.