Introduction
Cities and municipalities are under growing pressure to make their public infrastructure more efficient, sustainable and safer at the same time — typically within limited budgets. Approaches that build on existing infrastructure are therefore particularly attractive. Street lighting is a promising candidate: with hundreds of thousands of light points in Switzerland alone, it is one of the most widely distributed elements of public infrastructure, yet it has so far been mainly used as a light source. The standardisation of modular interfaces on modern streetlamps now makes it possible to rethink the streetlamp as a connected platform for sensing, communication and intelligent lighting control. The Innosuisse-funded research project "Smart Street Lighting with Object Detection and Analysis Capabilities", carried out by the FH Graubünden Institute for Photonics and Robotics (IPR) and esave AG, explores how this shift can be translated into practice.
Implementation
Within the project, a compact sensor module was developed that can be plugged onto existing smart streetlamps via the standard Zhaga interface, without any modification of the lamp itself. The module is designed to operate within the very tight power budget of 2W allowed by this interface, which has been a key constraint for similar systems in the past. Unlike conventional motion sensors, the new module not only detects that something is present but also recognises the type of road user below - for example car, truck, bicycle or pedestrian - and estimates speed and direction of travel. This richer information enables a more refined, situation-aware lighting control: brightness can be adjusted to the type of road user and to the direction of travel, so that light is delivered precisely when and where it is actually needed, lowering energy use while improving guidance and safety on the road. The same data can also serve as input for broader traffic management. Beyond the technical contribution, the platform also has an important ecological dimension: less unnecessary nighttime lighting means less light pollution, which is increasingly recognised as a major stressor for insect populations and other wildlife.
During the development, strict data protection was a key system requirement - all analysis runs locally on the device, no images are stored or transmitted and only aggregated and anonymised information leaves the sensor.
Conclusion
The project shows that a sensing platform with these capabilities can be realised within the very tight power and hardware constraints of the standardised lamp interface, which has so far been a major barrier for similar approaches. Compared to traditional methods such as induction loops, which need to be buried below the road surface, the modular sensor builds on top of existing infrastructure and is therefore highly scalable and cost-effective.
Further work
Ongoing work focuses on developing the current prototype into a production-ready solution suitable for broad deployment. A prototype is currently being evaluated in a long-term real-world test on a streetlamp in Chur. Beyond this immediate step, the platform leaves the door open to a wide range of possible applications. Examples include live traffic statistics, where continuous monitoring provides a basis for infrastructure decisions and the evaluation of measures; event detection, such as identifying stationary vehicles or other unusual situations on the road and parking-space management.