Technical and economic analysis of road lighting solutions based on mesopic vision

Although possessing considerably better colour rendering and more acceptable colour appearance than high pressure sodium (HPS) lamps, for economic reasons metal halide (MH) lamps are still rarely considered in road lighting. The results of previous theoretical and experimental research in the field of mesopic vision encouraged a comprehensive techno-economic analysis which compared financially road lighting solutions realized by MH and HPS lamps. Based on previous findings regarding both perceived brightness and visual performance, the analysis considered all relevant road lighting classes, lighting arrangements and reflection classes. It was proved that for lighting classes characterized by lower luminance levels MH lamps are economically comparative or even more favourable than HPS lamps.