Bike safety in mountain environments
Road traffic safety has always been a hot topic, as accidents on the road are still a major problem of modern society. To deal with this problem the research community has been working on inter-vehicle communications with the precise aim of preventing accidents from occurring in the first place, rather than trying to mitigate the consequences as passive safety systems do. Recently, we have seen an increased interest in Vulnerable Road Users (VRUs) research. Vehicle-to-pedestrian (V2P) and vehicle-to-bicycle (V2B) communications are currently under study as, differently from car passengers that are protected by the chassis, pedestrians and cyclists can seriously injure themselves even in small collisions.
Yet all the effort is focused towards urban areas, where the urge is higher due to the large presence of cars and the high density of people. For such contexts, we find a lot of studies on antenna placement and design, communication protocols, and on safety applications. What is not yet clear is whether existing communication and localization technologies would be sufficient to support safety application in mountain areas, where there is the risk of bike-to-bike collisions on MTB trails or bike-to-hikers collisions on shared trails. First of all the environment is very different, as foliage or even the shape of the track can lead to signal blockage. Differently from cities, infrastructure might not be present, meaning that devices might only rely on direct communication among them. In addition, localization also presents challenges as very often GPS positioning works poorly in mountainous areas or forests.
The research group of Prof. Michele Segata from the University of Trento in cooperation with the research group of Prof. Frank Kargl from the University of Ulm started investigating the above-mentioned issues by performing a measurements campaign in northern Italy. In particular, the team in Trento made by Prof. Segata and the master student Michele Zucchelli, focused on communication aspects, trying to understand the performance of two well-known vehicular communication technologies, namely IEEE 802.11p and Cellular V2X, in the aforementioned environments.
To this aim, the group mounted two cube:evk devices on a couple of bikes. As the cube:evk devices are small and consume little power, mounting them on bikes was relatively easy, and a single power bank was more than enough to perform a 10-hour measurement campaign. Moreover, the devices also offer GNSS positioning, Bluetooth Low Energy, and a WiFi interface, through which the group was able to remotely control the radios for the experiments.
Results
The research groups presented the results of the measurement campaign at the IFIP/IEEE WONS 2025 conference. During the campaign, the researchers mounted two cube:evk devices on two bikes, measuring the performance of IEEE 802.11p and LTE Cellular-V2X in terms of received signal strength and packet delivery ratio.
The results, which can be found in their entirety in the full article, show preliminary but very insightful results. In particular the results show how the terrain, which presents totally different characteristics compared to an urban one, can affect the signal in non intuitive ways. For example, the elevation loss typical of mountain trails, can result in an unexpected worsening of the signal strength as a bike comes closer to another one. In addition, steep hairpins can completely block the signal till the very last moment: this can lead to last-second reactions of the incoming biker which can, in turn, worsen the situation and cause further accidents.
In general, both technologies have proven to work reasonably well in the majority of the scenarios, but there are some specific cases where additional communication means might need to be considered to guarantee the safety of the riders.