The purpose of street and road lighting is to provide an optimal level of safety and accessibility for all. However, the right solution must also be cost-effective and energy-efficient and minimize light pollution. Ensuring that all these goals are met requires experience and expertise.
Lighting and road safety
The fact that proper road and street lighting reduces accidents is well documented in a number of international studies. Proper lighting can also improve accessibility and help create environments where people feel safe and comfortable. However, ensuring a suitable street and road lighting solution requires more than just adding more fixtures.
One of the important factors is that both the government and municipalities have limited resources. As with all public spending, priorities should be based on where and how the budget can benefit the people the most. Fortunately, we now have a deeper knowledge of how to best use lighting to reduce the risk of accidents.
In the last few decades, considerable research has been conducted on the relationship between road lighting and accidents. Some consistent findings are that road lighting causes:
۲۵% reduction in accidents resulting in personal injuries
۶۰% reduction in fatal accidents
۴۵% reduction in pedestrian accidents
۳۵% reduction in accidents at intersections
It’s no surprise that more light leads to increased security, but proper lighting is about more than quantity. It is important to ensure uniform light and the least possible light radiation to avoid large differences between different areas and along the road. This helps the eye to adapt and reduce glare from wet road surfaces. Proper shielding and placement of fittings at the proper height are important to avoid direct light and ensure proper light distribution.
In addition to these general considerations, the recommended amount of light is calculated based on key factors including road type, speed limit, average daily traffic volume (AADT) and surrounding environment.
One of the key goals for street and road lighting is to ensure pedestrian safety. To achieve this goal, lighting in pedestrian crossings is especially important. Dimly lit crosswalks may actually create a false sense of security and increase the risk of an accident. Poor lighting can make pedestrians believe they are seen and an oncoming car will stop, while the driver cannot see someone crossing the road.