Improvements in the quality of street lighting and the development of high performance retro-reflective signing materials potentially make unlit traffic signs more visible. TRL conducted a technical review, commissioned by Transport for London, into the requirement for local highway authorities to comply with the current statutory requirements for lighting traffic signs and bollards in areas with street lighting. As well as reviewing the regulations and the appropriate British Standards, a whole life cost benefit exercise was conducted. This covered the costs of different types of traffic signing material, their luminaires, life expectancy and maintenance. In addition, the costs, life expectancy and maintenance of alternative types of illuminated traffic sign were established. A workable guidance document was produced to inform local highway authority engineers when it is advisable and safe to relax the statutory requirements for lighting traffic signs and traffic bollards as part of a traffic management scheme in areas with street lighting. Practical guidance was also supplied covering the use of all types of lit and unlit traffic signs. Documentation was produced describing the process of obtaining official authorisation from the appropriate government department in order to relax the use of traffic signing without external illumination in areas with street lighting.
Other titles in this series:
SL1 ‘Review of the class and quality of street lighting’. G I Crabb, R Beaumont and D Webster. TRL Published Report PPR380. 2008
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
SL6 Guidance on the lighting requirements for traffic signs and bollard. J Cooper and J Mitchell. TRL Published Project Report PPR383. 2008

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