Cycling is a healthy, environmentally-friendly and enjoyable activity, which unfortunately also claims more than 2000 lives every year in Europe. Many municipalities across Europe are waging successful campaigns to increase cycling and, as a consequence, reduce pollution and congestion. However, at least in the short term, a surge in cycling is also challenging existing infrastructure, regulations, and the interaction among different road users. Further, the nature of cycling is changing as new electrified bicycles (e-bikes) become more prevalent, since they are able to maintain a constant 25km/h speed independent of road gradient or wind. The extent to which e-bikes prevalence impacts safety is currently unknown and very hard to simulate with statistical models. In 2012, the BikeSAFE project collected 1474 km of naturalistic cycling data from traditional bicycles. Similarly, in 2013, the e-BikeSAFE project collected 1549 km of naturalistic data from e-bikes. All studies took place in the urban area of Göteborg in the same period of the year, and involved the same participants as much as possible. While these naturalistic data sets are limited and possibly not representative of the cycling situation in all of Europe, they are also the most advanced data available today for comparing how traditional and electrical bicycles behave in traffic, thus offering a promising test bed for developing data analysis methodologies. Five random video clips of 30 seconds duration were extracted for each participant from the data collected in BikeSAFE and e-BikeSAFE, forming an overall analysis database of 140 full HD video clips. Video reduction identified which road users were involved in interactions with the bikes (traditional or electric). During the analysis, potential influencing factors (e.g. width, gradient, and curvature of the cycle path) were also taken into account. Information from the video reduction of e-bikes and traditional-bikes was compared by means of odds ratios and combined with subjective data from questionnaires, to determine the extent to which safety concerns about e-bikes are legitimate. Results show that e-bikes and traditional bicycles are ridden differently: cyclists riding e-bikes experience different, more frequent interactions with other road users, and prefer different riding conditions, possibly because of their higher speed. Further, infrastructure (such as crossings) and secondary tasks (such as using a phone) may be particularly dangerous for e-bikers. The results presented in this paper provide new ideas for the design of safer cycle paths and more conspicuous e-bikes. (Author/publisher)
Samenvatting