Warning system pilot at Viikki light rail crossing wraps up – System commended for enhancing safety

The pilot was located at the roundabout of Viikintie, Koetilantie, and Viikinkaari. The site was chosen for its complexity: the intersection area involves multiple directions of travel, and the light rail vehicles approach the crossing partially from behind commuters. They are also quieter than traditional trams. The introduction of the light rail also brought new types of crossings where pedestrians and cyclists are always required to give way to the light rail vehicle.

The pilot was implemented by the innovation company Forum Virium Helsinki, the City of Helsinki, VTT Technical Research Centre of Finland, and InnoTrafik Ltd – as part of the EU-funded ELABORATOR project. Vulnerable road users—such as cyclists, pedestrians, and the visually impaired—regarded the pilot as an important step toward improving crossing safety.

Multi-sensory warning captured attention

The system, supplied by InnoTrafik Ltd, activated as the light rail vehicle approached. It warned pedestrians and cyclists through multi-sensory alerts—including a yellow flashing light and voice warnings in Finnish and Swedish—while simultaneously sending a digital notification to the BlindSquare app, a common mobility aid for the visually impaired.

Of the 50 people who responded to the user experience survey, as many as 90% were pleased that the system was being piloted. The audio signal received positive feedback, as it was seen to improve safety when quiet light rail vehicles approach. Visually impaired users felt the warning system improved their safety and supported independent mobility.

Challenges and areas for development

While 68% of respondents were satisfied with the system’s impact on safety, the pilot also highlighted areas for improvement.

A warning device alone does not eliminate the structural challenges of a crossing, such as the lack of right angles, which makes navigation particularly difficult for the visually impaired. Consequently, visually impaired users hoped the device would also feature another kind of sound when a tram is not approaching, which would help them navigate themselves across the crossing.

There were also conflicting views regarding sound levels: while the warning sound can carry into nearby residential buildings on summer nights, it is crucial that the audio warning is clearly audible to those with hearing impairments. Furthermore, it remained unclear to some passers-by whether the flashing light indicated an absolute obligation to stop or served as a general warning.

VTT Study: Behavior became more cautious

VTT Technical Research Centre of Finland monitored the behavior of pedestrians and cyclists in the intersection area before and after the installation of the warning system. The aim was to determine how behavior changed as a result of the system and whether it improved traffic safety. The crossing was observed by recording traffic flow from the roof of a nearby university building.

According to the results, pedestrians and cyclists behaved more cautiously at the crossing—for example, by approaching it more slowly and waiting longer as the tram approached and passed the intersection. No actual accidents were observed, and “near-miss” situations were very rare. However, the more cautious behavior provides indications of safer traffic conduct.

The pilot was part of the broader ELABORATOR project, in which Helsinki is one of 12 European “Living Lab” cities. Funded by the European Union’s Horizon Europe research and innovation program, the project aims to promote safe and sustainable mobility in European cities.

For more information:

• Noora Reittu, Forum Virium Helsinki, Senior Project Manager, noora.reittu@forumvirium.fi
• Johannes Mesimäki, VTT, Researcher, johannes.mesimaki@vtt.fi
• Jouni Hänninen, InnoTrafik Ltd, jouni.hanninen@innotrafik.com

Photos and video: Vesa Laitinen