ADAPTIVE LIGHTING IN MOTORIZED TRAFFIC ROAD: REAL INSTALLATIONS SHOW THAT IOT TECHNOLOGIES CAN SUPPORT THE CORRECT USE OF STANDARDS

ADAPTIVE LIGHTING IN MOTORIZED TRAFFIC ROAD: REAL INSTALLATIONS SHOW THAT IOT TECHNOLOGIES CAN SUPPORT THE CORRECT USE OF STANDARDS Di Lecce, P., Mancinelli, A., Rossi, G., Frascarolo, M. Reverberi Enetec, Castelnovo nè Monti, ITALY, Reverberi Enetec, Castelnovo nè Monti, ITALY, INRIM, Torino, ITALY, Roma 3University, Rome, ITALY paolo.dilecce@reverberi.it Abstract 1. Motivation, specific objective In the world of Smart Cities and IoT, traditional pre-programmed street lighting dimming systems are perceived as obsolete. Capable of measuring three essential parameters for outdoor areas lighting control (traffic, weather conditions, and road surface luminance), a new generation of sensors is providing, at reasonable costs, opportunities for new approaches in both design and maintenance of road lighting installations. The standard EN 13201-1:2015 and CIE TR 115:2010, introduced specific chapters about new approaches of Adaptive Lighting: both lighting designers and Municipalities will be now able to operate real time PLMS (Public Lighting Management Systems) through sensors installed within their territories, with benefits in terms of energy saving and increased road safety. The new Italian standard UNI 11248 sets a number of parameters (dimming speed, maximum dimming levels, number and periodicity of samples, calculation parameters, control strategies, etc.) to ensure, in different real time measured conditions, maximum driving safety. The Italian standard introduces two adaptive lighting strategies: the TAI (Traffic Adaptive Installation), where only the traffic volume is measured and the FAI (Full Adaptive Installation), where even weather conditions and road surface luminance are measured. When FAI is being deployed and safety conditions are guaranteed, UNI 11248 allows a downgrade up to 3 lighting classes, corresponding often to 75% dimming of the luminous flux required by the initial lighting class. Even if these standards are requiring specific real-time measurements, more and more municipalities seem to be attracted by simpler Adaptive Lighting systems, able to detect only occupancy or movements. Clearly, according to standard for motorized traffic roads, this approach should not be considered. Such simple Adaptive Lighting systems well fit, with good results, in parks, gardens, or pedestrian area. On motorized traffic roads, the main driver visual task is obstacle identification, which is proportional to traffic flow and not to lane occupancy or movement. One reason that didn’t help Adaptive Lighting Systems diffusion was related to lack of technological advanced sensors, which did not give the possibility to install, on road, reliable traffic flow monitor and weather sensors coupled with luminance sensors. Today, with the help of computer vision technology, this is possible. Unfortunately, sensor cost and limited analysis area are negatively influencing a broader diffusion. 2. Methods Thanks to EU program LIFE, an innovative approach has been designed and applied in the city of ROME, within EUR district, with the project LIFE-Diademe. Today, the IoT technology (Internet of Things) is allowing to install, on each lighting pole, low cost sensors, able to detect luminance, traffic flow and weather conditions. All these parameters can be measured in a more accurate way and, above all, in a wide urban area. Within the LIFE-Diademe project, 1000 devices have been installed on 1000 lighting poles, to measure, in a selected area, relevant parameters for Adaptive Lighting. For obtaining a wide records of typical road lighting situation, the tests considers urban contests representing different type of traffic: residential, offices, shops, Public Administration, University, etc. On-site expert systems analyse streets data and, thanks to the 3 basic evaluated parameters, they adapt street lighting levels in real time mode (measurement and dimming time is executed every minute). 3. Results To set the base line, a complete lighting measurement campaign has been executed for the 1000 lighting points through EUR Rome. For different pre-set light levels, visual luminance, lighting point luminance, street light uniformity (transversal and longitudinal), pedestrian zone lighting levels and power absorbed by each control panel has been collected. Then the new LIFE-Diademe system has been installed. First data about behaviour of the system are showing an approximate energy saving of about 30% compared to pre-programmed dimming cycles, and 50% compared to no dimming. These data are comparable with other Adaptive Lighting installations – designed according to standards – where the most significant result is that in most of the urban roads, for 90% of the time, traffic flow is less than 10% of road nominal capacity. Thanks to new IoT concepts, data about air quality, noise and pole inclination will also be collected from each lighting point. 4. Conclusions The LIFE-Diademe project experience will run for one year. This permits to collect a reasonable sets of data. After this period, a new lighting measurement campaign will be performed and, consequently, a Life Cycle Assessment (LCA) and a Life Cicle Cost Analisis (LCCA) analysis will be carried out, in order to asses results, in terms of energy saving, safety, waste reduction, and, finally, sustainability