We are in a time of considerable debate regarding street lighting and public safety. Many councils are questioning decisions made to dim street lighting or switch them off for part of the night; a practice known as ‘adaptive lighting’.
The Institution of Lighting Professionals (ILP) urges those with responsibility for street lighting to refer to Professional Lighting Guide 08: Guidance on the Application of Adaptive Lighting within the Public Realm (PLG08) which was published in 2016. This document describes a process for assessing the needs of road users during the night and suggests reductions in the amount of light can be justified as vehicular and pedestrian traffic decreases after the morning and evening peaks. What PLG08 does is guide the lighting professional through stages of data gathering, data processing consultation and analysis in order to ascertain whether lighting can be reduced or even switched off for part of the night.
PLG08 is current; its processes and recommendations suggest the decision for lighting reduction or switch off should be kept under regular review, to ensure the data and feedback used still justifies the actions taken. For many, energy and carbon reduction were drivers during the decision-making process. The replacement of old street lighting with dark-sky friendly LED will reduce energy consumption for most by around 60%. This reduction could offset a reversion from part night to all night lighting.
A lighting professional, using PLG08 and other guidance including ILP GN01 Guidance For the reduction of obtrusive light (2020) will be able to review the decision-making process and offer advice on the options available.
PLG08 is available as a digital version free of charge to all members of the Institution and can also be bought from: https://theilp.org.uk/publication/plg08-guidance-on-the-application-of-adaptive-lighting-within-the-public-realm/
Guidance Note 01 is available free at: https://theilp.org.uk/publication/guidance-note-1-for-the-reduction-of-obtrusive-light-2020/