TRL was commissioned by TfL to carry out research into the class and quality of street lighting on all types of road on behalf of the sponsoring group. The methodology included a review of standards and guidance documents, a review of costs of a range of lighting equipment and a survey of local authorities’ policies and specifications. The report presents the results of the desk study and an analysis of the questionnaire returns. The cost information was used in a whole-life-cost calculation of the hardware and energy costs over a 30-year life, to compare four types of lighting system. These were conventional HPS lamps with electromagnetic gear, HPS with non-dimming electronic gear, Philips Cosmopolis White lamps with similar electronic gear and an HPS system with electronic gear, part-night dimming and central control and monitoring.
The results showed that most of the authorities specify selection of lighting classes within the range of the current British Standard, but that this standard is relatively inflexible compared to the parallel European document. This may in some cases result in the selection of unnecessarily high lighting classes. Most authorities have policies on lamp type, but few have policies on dimming, full or part-night extinguishing, central monitoring and control or passive safety.
The WLC exercise demonstrated that although the more “advanced” systems use the least energy, higher initial costs result in WLCs over 30 years being similar. There should therefore be no serious financial impediment to the installation of the more advanced systems. The report concludes with a set of recommendations which should help local authorities specify optimum lighting for all lighting situations.
Other titles in this series:
SL2 ‘Invest to save – sustainable street lighting’. P Fox. Mouchell. 2008
SL3 ‘Review of luminaire maintenance factors’. A Sanders. Mott MacDonald. 2008
SL4 ‘The use of passively safe signposts and lighting columns’. GL Williams, J V Kennedy, J A Carroll and R Beesley. TRL Published Project Report PPR342. 2008
SL5 ‘Review of the lighting requirements for traffic signs and bollards’. J Cooper, K Stafford, P Owlett and J Mitchell. TRL Published Project Report PPR382. 2008
SL6 Guidance on the lighting requirements for traffic signs and bollard. J Cooper and J Mitchell. TRL Published Project Report PPR383. 2008
elp local authorities specify optimum lighting for all lighting situations.

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