LED (Light-Emitting Diode) Road Lighting in Practice: An Evaluation of Compliance with Regulations and Improvements for Further Energy Savings

Abstract

Light-emitting diode (LED) road lighting has been widely implemented in recent years, but few studies have evaluated its performance after installation. This study investigated whether LED road lighting complies with minimum regulations in terms of traffic safety and whether improvements for energy efficiency are possible. Average road surface luminance (L), overall luminance uniformity (U o ), longitudinal luminance uniformity (U I ), power density (P D ) and normalised power density (P N ) were evaluated for 14 roads (seven designed for vehicular traffic and seven for pedestrians and bicycles). Energy savings were calculated as the percentage reduction to the minimum level of the existing lighting class or a lower lighting class and by applying a dimming schedule. The results showed that LED road lighting for vehicular traffic roads generally fulfilled the requirements, whereas that for pedestrian and bicycle roads generally corresponded to the lowest lighting class for L, and often did not meet the statutory requirements for U o and U I . By adapting lighting levels to the minimum requirement of the existing lighting class or by dropping to a lower lighting class, vehicular traffic roads could save 6%-35% on L to lighting class M5 and 23%-61% on L to lighting class M6. A dimming schedule could lead to energy savings of 49%. There is little potential for savings on pedestrian and bicycle roads, except by implementing a dimming schedule. Thus, in general, for vehicular, pedestrian and bicycle roads, a dimming schedule can save more energy than can be achieved in general by reducing lighting class. Furthermore, since a dimming schedule can be adjusted to traffic intensity, any potential risk of compromising traffic safety is minimised.

Evaluation Between Energy Efficiency, Ecological Impact and the Compliance of Regulations of Road Lighting

“…Values of AECI seems to be low compared with the typical values between 0.6-3.8 for LED on various types of roads (CEN, 2016b). However, power demand per kilometre road is similar to previous studies of LED road lighting, varying between 937 -2833 W/km (Jägerbrand, 2016).…”

Single-Switch LED Post-Regulator Based on a Modified Class-E Resonant Converter with Voltage Clamp

“…If the input and output voltages are equal the power recycled will be null. The availability of better light sources has also been considered by many public administrations to push the specifications required for new installations to higher levels [7,8]. Furthermore, even the metrics used to characterize light sources have had to adapt to the new possibilities associated with the use of solid-state lighting systems.…”

The Electric Bicycle: Worldwide Research Trends

“…As expected, the field of engineering leads the research, since it covers facets such as transport [31], the development and manufacturing of a product [32], innovation in materials to lighten bicycles [33], and electrical issues related to batteries [34]. Computer science deals mainly with the design [35], distribution of energy to the charging batteries [36], issues related to safety [37], behavior [38], and Medicine to Accident Analysis and Prevention [39][40][41][42].…”