Adaptive road lighting stands as a fundamental component for the development of Smart Cities, integrating sustainability and energy efficiency with pedestrian safety and comfort into a single intelligent system. In the urban context, street lighting adjusts its intensity and light pattern based on real-time data, prioritising the specific needs of the city’s streets and squares.

This proactive approach responds to the critical need of administrations to reduce high municipal electricity consumption and improve the nocturnal liveability of their environments.

1. Energy efficiency and intelligent consumption management

Outdoor lighting represents one of the largest items of energy expenditure for municipalities, consuming between 40% and 60% of their total electricity. The implementation of adaptive lighting, based on high-efficiency LED luminaires and tele-management systems (LMS – Lighting Management Systems), allows for unprecedented optimisation.

  • Demand management and dynamic dimming: The key strategy is selective dimming. Instead of maintaining constant power throughout the night, light intensity is modulated automatically. During hours of low activity, especially in the early hours of the morning or on secondary streets, power can be reduced to minimum levels of 20-30% of total capacity. It only increases to 100% instantaneously and gradually upon the detection of a pedestrian, cyclist, or vehicle.

  • Sustainable savings and KPIs: This intelligent management can generate energy savings of between 50% and 75% compared to traditional lighting. This saving translates directly into a significant reduction in the municipal carbon footprint, contributing to the UN Sustainable Development Goals (SDGs) and energy transition commitments.

  • Predictive maintenance 4.0: The tele-management of each light point (node) facilitates remote monitoring. The system automatically detects and alerts regarding voltage failures, power variations, or imminent luminaire failures (detection of flickering or low performance). This transforms maintenance from corrective to predictive, optimising human resources and avoiding service interruptions.

2. Road safety and nocturnal risk mitigation

In the urban environment, lighting is a key factor in accident prevention, especially at critical interaction points between vehicles and pedestrians (junctions, zebra crossings, public transport stops). Insufficient lighting not only generates citizen insecurity but also increases the risk of accidents.

The link with risk in the dark: Specialised studies demonstrate the direct relationship between a lack of light and an increase in accident rates. The recent report on accidents caused by running off the road by INTRAS (Institute of Traffic and Road Safety) corroborates this need. Although the study focuses on interurban sections, its conclusions are fundamental: deficient visibility is directly linked to a higher percentage of accidents, with the risk increasing when the road lacks artificial light. Prolonged darkness reduces the driver’s perception capacity, especially regarding static objects on the carriageway or stationary vehicles, increasing the probability of head-on collisions or running off the road.

Adaptive lighting in Smart Cities mitigates this risk through:

  • On-demand activation (tactical dimming): By increasing light only in the presence of a user, the system guarantees maximum visibility at the precise moment a potential risk arises.

  • Prioritisation of pedestrians at crossings: Through sensor detection, light intensity over zebra crossings can be increased in a focused manner, protecting the most vulnerable users and giving them visual priority.

  • Comfort and liveability: It generates a sense of safety and well-being, promoting the use of public space and active mobility (pedestrian and cycling) during night hours, a key factor for quality of life in Smart Cities.

3. Lighting as an IoT platform and source of urban Big Data

The true leap in adaptive lighting is its transformative role as an IoT (Internet of Things) platform within Intelligent Transport Systems (ITS). Smart City luminaires no longer just emit light; they act as a dense network of sensors connected to centralised management software.

  • Sensors for mobility management: Lighting nodes equipped with motion sensors, radar, or low-consumption cameras become urban data collection points.

    • Flow Control: They measure traffic density and pedestrian flow in real-time to optimise lighting and generate mobility heatmaps.

    • Integration with Emergency Platforms: The lighting system can connect with the traffic network. If an accident is detected or an emergency vehicle approaches, the lighting in that section automatically increases to improve visibility and clear the road.

  • Multi-Purpose Services and connectivity: The lighting infrastructure becomes an essential support for other Smart City services, offering value-added solutions:

    • Environmental monitoring (air quality, noise).

    • Charging points for electric vehicles or bicycles.

    • Hotspots for the deployment of public Wi-Fi or low-power 5G networks.

  • Informed planning (Big Data): Anonymous and aggregated data collected by luminaires (pedestrian flow, environmental data, usage patterns) are processed as Big Data for urban planning, helping authorities make precise decisions regarding the design of sustainable infrastructure (location of cycle lanes, changes in transport routes, or reorganisation of public spaces).

4. Environmental sustainability: Reduction of light pollution

A benefit often underestimated in adaptive lighting is its contribution to environmental sustainability, specifically through the reduction of light pollution.

  • Dark skies: By modulating intensity and directing the light beam (thanks to advanced LED optics), light projected towards the sky (upper hemisphere flux) is minimised. This protects nocturnal ecosystems, reduces the impact on fauna (especially birds and insects), and allows citizens to enjoy a less polluted night sky.

  • Spectral adjustment: The ability to select the colour temperature of LED light (generally below 3000K) reduces the emission of blue light, which is the most harmful to human sleep cycles (circadian rhythms) and generates the most light scattering in the atmosphere, contributing to a healthier urban environment.

Intelligent lighting transforms street lighting from a fixed and passive service into a dynamic, efficient, and central element in the digital and sustainable management of Smart Cities.