Efficiency Analysis of Roadway Lighting Replacement in a Selected Polish Municipality

Abstract

The paper addresses the problem of the efficiency of road lighting replacement in a selected municipality. The following question arose: can the replacement of lighting bring measurable financial benefits in the short or long term, and does increasing the comfort of road use in terms of lighting involve higher costs? During the global energy crisis, reducing the operating costs of road lighting has become the goal of many analyses and studies. Professionally selected lighting of streets and sidewalks is a factor that significantly affects the safety of road users. The problem of many studies is the omission of safety considerations, lighting comfort and budgetary possibilities of municipalities. The authors conducted comparative analyses of solution variants, examining both road lighting comfort and costs as an innovative element of research. The DIALux application was used to analyse the changes in road lighting depending on the luminaires used and the changes in pole spacing influenced by the height of the light point. Variant and scenario analyses were incorporated into the efficiency analyses, while the calculations themselves were based on detailed cost analyses with reference to Polish catalogues of material inputs and market prices. The authors conducted cost analyses of lighting dismantling and installation, including the subsequent operating costs over 20 years for seven variants of poles with their systems and four variants of luminaires. The results were compared with the existing lighting system in use. An original element of the study is the use of BIM analyses with design variants, combined with analyses of the technical condition of the existing lighting network and an illuminance analysis with estimates of the height and spacing of poles. Numerous studies indicate that it is very cost-effective to replace old lighting systems, especially those based on high-intensity discharge (HID) sodium lamps, with more modern LED lamps additionally equipped with twilight dimmers. The analyses also demonstrated that cost-efficient lighting replacement could go hand in hand with improved road lighting comfort without the need to incur additional costs, which is often overlooked in various studies. The analysis performed for a model lighting network indicates that savings of nearly 60% are possible over 20 years.