Road Surface Photometric Characterisation and Its Impact on Energy Savings

Abstract

How road surfaces reflect light in space is a physical characteristic that plays a key role in the design of road lighting installations: by European Standards the average luminance is the target quantity to assure the required safety conditions of the motorized road traffic. Lighting systems are designed (luminous flux installed per kilometre) to comply with the above requirement, starting from reference values of road surfaces reflection published in an old scientific document. These data are obsolete and not representative of current road surfaces, but they are still used to design current LED lighting systems. European Community funded a SURFACE project to provide to EU standard organization new traceable reference data, representative of current road surfaces used in EU. The paper presents the data collections and the impact on road lighting of using available old reference data versus SURFACE collected data of current road surfaces. Results highlight advantages in using bright pavements as well the need for introducing systems for flux control in road lighting installation to compensate for the discrepancies between current reference data and actual road surface data.

Towards an Optimization of Urban Lighting Through a Combined Approach of Lighting and Road Building Activities

“…As in (Chain, 2007); (Christory, 2014); (Muzet, 2018), (Gidlund, 2019), these results confirm the importance of measuring and taking into account the actual photometry of pavements. The impact of initial treatment is good because it decreases the specularity and then, the uniformities are closer to the standard requirements.…”

“…The aim of the lighting calculations is to assess the impact of the use of the characteristics of actual surfaces. We compare all our calculations to the reference CIE r-table R3 (CIE, 1984), because it is used in France for lighting design and close to the CIE r-table C2, which is used in different European countries (Gidlund al., 2019). In order to assess the impact of the pavement and luminaire photometry, we propose several approaches: Since the study is still going on, we focus here on 2 typical lighting installations proposed in the standard (CEN, 2015e) and a small set of pavements from our database with very different photometry.…”

Optimization of Road Surface Reflections Properties and Lighting: Learning of a Three-Year Experiment

“…The collection of on-site photometric measurements will also be an input for the European SURFACE project (EMPIR, 2017), (Gidlund, 2019) which collects the r-tables of current and innovative road pavements across Europe in the context of a pre-normative study.…”

Innovative Design and Metrological Approaches to Smart Lighting

“…These are the expected outcomes of the project Surface that was involved in the workshop of PoliTo and INRIM too. Moreover as highlighted in a recent study [Gidlund 2019] the use of bright pavements can provide relevant advantages in energy savings, but also in pedestrian visibility and comfort. In this case the relevance of the knowledge of radiant q quantity and ILMD spectral sensitivity play a relevant role.…”