|Christian Weber, Hanne Beate Sundfør, Aslak Fyhri
Bicycle helmets have been subject to much debate. One important topic for discussion is the degree of risk compensation associated with their use. Previous studies have showed that participants who are given no time, or a short time (two hours) to get accustomed to the helmet do not increase their speed when wearing one. Studies were participants wear a helmet for several weeks to test the long term speed change effects are called for. The current study is a longitudinal field experiment of risk compensation from helmets. Nonroutine helmet users are recruited in the field (N=40). Half are randomly selected to the test group and half are selected to a control group. The participants in both groups are instructed to download an application (Blue.TOI) which automatically detects a bicycle trip and logs speed (+/1 kmh) and GPS coordinates. The study consists of a pre-trial period where none of the users wear a helmet, and a trial period were the test group are instructed to wear a helmet for all trips. The control group are not given any instructions. The trial period lasts for three weeks. We compare average changes in speed from pre-trial to trial period between users and non--users. Further, we test for a time effect. Data will be collected in August 2016, and results are presented at the conference. The research design with the precise and objective data from the app, makes it possible to draw quite strong conclusions about the risk compensation effects of the helmet. Possibilities for other behaviour measurements (accelerometer/gyro data) are discussed.