The popularity of electric bicycles, so called pedelecs, has increased rapidly over the last few years. Their numbers are expected to grow even further in the years to come. Given this increase in prevalence, new challenges for road traffic arise. The effects of potentially higher speeds that might be achieved with electric bikes on road safety are unclear. Likewise, the fact that older riders currently are the main user group for this type of bike leads to questions about physical fitness and increased safety risks. Changes in overall mobility behaviour can be a consequence as well. Within this project, aspects of mobility and safety behaviour of cyclists were investigated in a so called naturalistic cycling study. Core of this methodological approach is the instrumentation of bicycles with cameras and other sensors to observe riders over a specified period of time, to capture riders’ “normal” cycling and mobility behaviour. Overall, 90 cyclists were recruited for this study. Forty-nine of them were owners of a pedelec25. This type of electric bike, which supports pedalling up to a speed of 25 km/h, is treated legally like a regular bicycle. Ten participants were riding pedelec45, which support pedalling up to 45 km/h. When using this kind of electric bike, riders are required to use a helmet, and the bike needs to carry a license plate. An additional 31 participants were recruited that drove regular bicycles. To account for potential age effects, roughly one third of the participants was 40 years or younger, between 40 and 65, and 65 or older, respectively. Each of the 90 participants was observed with the instrumentation over a period of four weeks on his/her trips. In addition, for one of the four weeks, participants were required to fill in a mobility activity diary to track all of their trips (not just bike) and trip purposes. Furthermore, they completed questionnaires regarding aspects such as user behaviour and accident history before and after data acquisition. Overall, more than 4,000 trips with a total length of roughly 17,000 km were recorded. To uncover potentially safety relevant traffic situations, an extensive video annotation was conducted. To accomplish this, every single trip was screened for potentially critical situations, which were identified and annotated using a predefined coding scheme. In addition, trip length, trip duration and especially speed were analysed using wheel sensor data. The results of the study show that the use of electric bicycles did not result in an increased number of critical situations compared to regular bicycles. Age did not affect the relative frequency of occurrence of critical situations as well. When taking into account the different conflict partners, it appeared that most frequently, cyclists and ebike riders experienced conflict situations with motorised vehicles such as cars or lorries. However, also a substantial number of conflicts between (electric) bicycles and pedestrians could be found. The analysis of the sensor data revealed the expected differences regarding average riding speed. On average, pedelec25 riders travelled somewhat (ca. 2 km/h), pedelec45 riders substantially (ca. 8 km/h) faster than riders of regular bicycles. There were also profound age effects in the expected direction. In contrast, relevant differences in mobility behaviour between bike and e-bike users could not be found. Given the results of this project, the current regulations, which treat pedelec25 as a regular bicycle, and put up stronger requirements for the use of pedelec45, appear to be reasonable. The comparable number of critical situations for all three vehicle types suggests that the risk to be involved in an accident is not increased for electric bicycles. At the same time, however, the fact that pedelec45 are travelling, on average, much faster than the other two vehicle types, suggests that the risk of severe injury in case of a fall or a collision is considerably higher for the faster e-bikes. Overall, however, it appears that a continuing assessment of the issue is required. Currently, user groups and use cases for the different types of bikes and e-bikes differ substantially. Whether there will be transformations within the user groups, and whether this will result changes in road safety relevant measures, needs to be closely observed. (Author/publisher)
Abstract