The design of lighting installations on roads and urban infrastructure has strictly followed the regulatory requirements of each country for a long time. Based on the traffic intensity, the presence of pedestrians and the nature of activities within the area, these regulations have been used to establish the luminance or illuminance levels from or on the pavement, the minimum average uniformity, the maximum glare and the minimum energy efficiency. Accurate values of these static parameters are supposed to ensure safety, security, and efficacy, and have traditionally been considered as the main targets of lighting installations. Therefore, compliance with these regulations indicates whether an installation is legal or not. Although this philosophy is operative, the reality is different due to two main issues. First, the progressive ageing of populations, mainly in North America and Europe, the changing circumstances of traffic flow and modalities and the presence of groves or socioeconomic factors, might have a strong impact on the safety, security and sustainability of cities. Secondly, the current regulations leave out perceived safety and security issues, as well as the well-being of people; that is, how people feel about the city independently of real danger. In this research, the Basic Process of Lighting (BPL) is formulated including, for the first time, the human factors involved when people develop their activities under public lighting. Using this framework, the potential factors influencing human wellbeing and feelings are summarized after being rated by people in a survey distributed among 133 participants. The results highlight a higher perceived impact of social factors compared to physical and visual ones.

The control and efficient use of daylight is a difficult task due to its seasonal and hourly variation. Although it is matter of active research in indoor lighting due to the necessity to light human tasks at any hour of the day in a sustainable way, little attention has been paid to the impact of daylight on visual performance, safety and ergonomics of citizens, especially pedestrians in urban areas. This attention is even lower when dealing with the interaction between daylight and urban groves, which is an essential element in cities due to a wide variety of benefits like shadowing, CO₂ absorption, natural aesthetics, noise protection and many others. In this work, the interaction between daylight and typical urban trees in one city with high levels of insolation (Granada, in southern Spain) has been studied. The results, conclusions and proposals for a more sustainable urban planning are analyzed and presented.

Although the realm of sustainable development has been sharply associated with energy savings and a decrease in contamination, the concept deserves a much more comprehensive approach. Sustainable development, as the only respectful and safe way to progress, involves—besides the mentioned rational use of energy and resources—a broad variety of economic, technical, cultural, and behavioral issues. In this context, the total or partial recovery of abandoned singular infrastructure facilities for alternative uses (leisure time activities for human welfare) is to be considered an original, interesting, and efficient approach. In this research, the so-called “El Caminito del Rey” [The King’s Little Path] will be studied as a paradigmatic model of successful achievement. The path is located in Málaga, South of Spain, and was originally built to provide access to a hydroelectric power plant. Due to the construction of new routes, the track and walkways were progressively abandoned. The recovery enterprise was conceived in the framework of circular economy-based planning and with full respect to environmental requirements. The facts and figures that will be presented and analyzed will show that when the project is thoroughly designed and carefully implemented, the rehabilitation of obsolete infrastructure facilities located in natural spaces is suitable, feasible, and profitable. Prudent and rational use of these assets for alternative purposes (human welfare through rural tourism and open-air activities) may be fruitful not only in economic terms but also in environmental, cultural, and social ones. The main objective of the current work is to demonstrate that obsolete abandoned facilities can be rehabilitated into worthwhile amenities that may turn into key factors for the sustainable development of determined rural areas. Moreover, the “El Caminito del Rey” experience could represent a model for similar development projects.