A few residents have recently contacted me to ask why the M25 is no longer lit at night, so I wrote to National Highways to find out what had changed and the reasons behind it. I recently received a letter back from them which included the following:
"Some sections of lighting on the M25 have been switched off, after a safety assessment, as part of our work to reduce carbon emissions. This includes the section between Junctions 6 and 9 which the residents in your area have noticed.
At National Highways, we have been reviewing motorway street lighting as part of work towards carbon reduction targets to see if lights can be switched off without reducing safety on the network. We have been looking at this because reducing the use of lighting, where it is safe to do so, will help to reduce carbon emissions. It also has environmental benefits for wildlife and helps to cut light pollution.
We do understand that customers will notice when lighting has been switched off and will have questions. Before the lighting was switched off, we completed an assessment using the Road Lighting Appraisal document TA 501 (formerly TA 49/07). TA 501 is part of the Design Manual for Roads and Bridges (DMRB) and it is used to assess the case for new and replacement lighting on motorways and all-purpose trunk roads.
The assessment looks at the collision data for the route and the traffic flows and advises whether the lighting at that location would have a benefit for road users' safety. If lighting is switched off, then we follow this with an 18-month assessment period. This means that the lighting infrastructure remains in place and we keep the locations under review. If it is considered necessary, then the lighting can be switched on again.
The lighting on the M25 between Junctions 8 and 9 was switched off in December 2023, and so the 18-month period will finish in June 2025. At the end of the 18 months, another TA 501 assessment will be carried out to consider whether the lighting should be removed.
Not all the lighting has been switched off. At the junctions, some lighting will be removed, but the area will remain lit. This is to help road users to adjust between the different light levels on the M25 main carriageway and the local network.
We have been asked why the lighting is being switched off, rather than being converted to LED. We have a National Highways LED Roadmap which states that a TA 501 assessment should be carried out as part of the assessment for conversion to LED. The lighting at these locations has been assessed for conversion to LED, but the assessment was that there was no justification for replacing the lighting with LED luminaires."
I have some concerns about the lights being switched off, as I personally think safety on the M25 should always be the highest priority. Also the above letter doesn't explicitly confirm what the risk assessment concluded with respect to whether lighting along this stretch has a benefit for road users' safety. I will write back to National Highways accordingly. Please email me at [email protected] if you have any thoughts on the above or wish to share your recent experiences of driving along the M25 during the night.
