Paradise Street Footbridge illuminated at night. Credit: David Heron

+ Night-time lighting levels should correspond to activity on city streets and pavements.

Turning off street lights at an arbitrary time such as midnight may appeal to city leaders. After all, doesn’t it save both money and energy? I don’t believe it’s this simple.

Instead, I think the rise and fall of public lighting in a city should be determined by the activity on its streets and pavements. This more nuanced approach would see light provided when it’s needed.

For example, if all the restaurants and shops in an area are still open at 8pm, their lights may be enough to illuminate the street. So public lighting may not need to be on at this time, at least not at full power.

But at 11pm, say, there may be shift workers going home or clubbers going out. With shops and restaurants now closed, there would be no private light spilling onto the street and public lighting should be on to help people travel safely and securely.

Some cities around the world are experimenting with this approach. Glasgow is trialling ‘intuitive’ street lighting that responds to factors such as noise. I think cities need to make use of new technology in this way. But they also need to engage with the issue more fundamentally.

I’d argue that cities need lighting committees in the same way they have planning committees. These would build an understanding of an area, including predicted, planned development, of how people will use the public space and therefore how it should be lit.

I also think it’s essential to involve local communities in this process. In Cartagena, Colombia, Arup is researching how to create high-quality night-time public spaces. As part of the project, districts are invited to explore their after-dark hours, highlight dark spots and gaps – those that are unsafe or unwelcoming – and influence design decisions.

Ultimately, night-time is essentially different from daytime. So it deserves its own design approach, and thinking creatively and smarter about street lighting is a vital part of this.