The CSS, the organisation that represents Local Authority Chief Officers in the UK, has defended a series of trials designed to test the benefits of switching off and dimming street lights during part of the night. The trials being undertaken by some local authorities have come under fire in the Daily Mail amidst fears that they will encourage crime and reduce road safety.

But CSS, which represents local authority strategic directors responsible for the environment, transport and energy, says that it is important to understand the pros and cons and to give local communities an opportunity to comment. It also stressed that the key issues involved were light pollution and carbon reduction rather than cost-saving.

Roger Elphick, Chair of the CSS Street Lighting Group and of the UK Lighting Board, said: "There is pressure on local authorities to reduce energy costs and balance that with road safety costs and crime reduction, but there are many other options available for reducing energy costs as well as turning off street lights. Lights can by dimmed or set so that they come on later and go off earlier or may be turned off in rural areas. "One of the reasons for the current trials by a number of local authorities is to see what the impact is and what the public reaction is, so it's not wrong to run these trials."

Last year, the CSS initiated five street lighting research projects as a significant step in the development of guidance and best practice for the lighting industry and local authorities. The projects pull together a number of innovative strands on energy management and minimising the carbon footprint from local authority lighting. The results of the projects will be made available in the summer of this year.

These are a follow-up to the Invest To Save guidance issued by the UK Lighting Board about 18 months ago.

Mr Elphick added: "These projects will help in assessing the benefits of various energy-saving initiatives and establishing appropriate lighting levels for different street types and locations." Alison Quant, CSS Vice-President and Director Environment at Hampshire County Council, added: "The Daily Mail article presents the switching-off of street lights at night as a cost-saving issue, whereas in practice part-night lighting and dimming are not likely to save money in the short-term because of higher capital costs, but could have quite big impacts on our carbon footprint and reduce light pollution.

"Street lighting accounts for a significant part of a council's carbon footprint, and with the Climate Change Bill going through Parliament, the UK is signing up to reductions in our carbon footprint of at least 60 per cent by 2050. In addition, energy costs have been going up fast and are likely to continue to rise, placing an additional burden on council tax payers. "Technology changes are making lights more energy-efficient and it is possible to control street lights in more sophisticated ways, so as street lights are replaced it makes sense to ask what levels of lighting we want in the future. To answer that question, a number of authorities are trialling dimming and part- night lighting to see what effect it has and what residents think about a different approach.

"Arguably, the best result would be achieved if all lights had the potential to be dimmed or switched off by timers, but the extra cost this would add to each street light will probably rule this possibility out unless enough energy cost savings can be guaranteed. Trials like this will help councils make that judgement."