Public road lighting during night-time is essential in citizens' daily lives. In recent years, investments in efficiency of street lighting have been done at all levels: European, national, regional and local. A switch to LED technology is taking place as pilot projects. It is expected to provide the same lighting quality, reduction of costs and increasing energy efficiency. In this investigation, the relationship between illumination during the daytimedarkness period and the number of road accidents resulting in fatalitieswas studied for the Loures County. It was found that the largest number of fatalities occurred during the darkness period. Fatalities decreased between 2000 and 2015. The energy efficiency of Loures increased and at the same time, there was a decrease in the number of accidents resulting in fatalities. It is concluded that the quality of public light may contribute to reducing loss of human life in road accidents.