So a major study led by the London School of Hygiene & Tropical Medicine strongly indicated that reducing street lighting in the small hours had no effect on crime or on vehicle collisions. Then some motoring groups came out with some anecdotal examples to say that the opposite might be true. There are groups convinced by the environmental benefits of reducing street lighting, others convinced of the health benefits of reducing light pollution, and still others who are worried about personal safety in dark or dimly lit streets.

But the emergence of new technologies always disrupts predictions based on historic data, which can only measure incremental change. Most of the data in this study inevitably comes from the early days of streetlight control, where large populations of lights could be switched off en masse or dimmed slightly.

Today’s streetlights have built-in wireless intelligence. It means they can make individual minute-by-minute decisions based on policies set by the city authority, knowing under what conditions to switch on, when to dim and and by how much. This way, city authorities can adapt the way the city is lit, street by street and light by light. This can be based on centrally held data, such as traffic patterns or pedestrian footfall. Or they could be set to meet different community priorities, for example to reduce light pollution or to reduce the fear of crime. And each light can also act automatically on other Smart City sensor inputs such as traffic detection and fog. All of this is deployed today.

You can’t use historical data to predict the effect of a precise adaptive lighting environment like this on citizen behaviour, or whether as a result people will feel differently about their neighbourhood. Because these innovations are still very recent. The good news is that smart city technology like wireless streetlight intelligence means that authorities now have the power to take control and refine their street and highway environments to meet their citizens' needs.