As the saying goes, "You can't forget how to ride a bike". However, pedaling while keeping your balance is not enough to get around town, which requires learning a combination of explicit knowledge (rules), advice and even injunctions (positioning on the road, etc.), tactics (adapting to a territory designed for cars) and tacit knowledge (experience).

This project focuses on intersections, which are accident-prone areas for cyclists. Two measures have been taken to improve cohabitation with car traffic. At some intersections with traffic lights, cyclists are allowed to perform right-turn-on-red maneuvers at traffic lights if the appropriate sign is displayed, but this recent rule is not well known. At roundabouts, it is recommended that cyclists take their place on the carriageway, but this measure is hampered by the difficulties of owning the road motorized traffic and the "looked-but-failed-to-see" phenomenon of motorists.

These measures raise important road safety issues. However, we do not know (1) the proportion of cyclists adopting these behaviors, (2) the differences according to age, gender, type of bike, etc., (3) the reasons for (non) adoption of these measures (lack of safety, information, confidence, etc.) and (4) the effect of intersection configuration.

In Lausanne, the project is studying 10 intersections with traffic lights (5 with right-turn-on-red, 5 without) and 5 traffic circles, where observations and intercept surveys will be conducted. An exploratory phase will also include processing automated video data from traffic cameras through algorithms.