Cyclists' choice of lateral position and feeling of safety between tram tracks, sharrows and parked cars

Cycling is good for the environment, healthy and affordable [1 ]. However, these benefits are offset by the risk of being involved in traffic crashes [1], with infrastructure characteristics like tram tracks or parked cars increasing aforementioned risk [2, 3]. Bicycle crashes with tram tracks can occur when cyclists turn onto streets with tram tracks or cross them for other reasons, such as avoiding parked cars on the side (oftentimes related to sudden maneuvers to avoid collisions with the door of a parked car being opened) [4]. Such collisions, referred to as dooring crashes, account for a significant proportion of bicycle crashes [3]. Nevertheless, the majority of cyclists ride in the so-called dooring zone, which is the area next to parked cars where dooring crashes can occur. If the cyclists' lateral distance to parked cars is large enough, the risk of being involved in a dooring crash can be eliminated [2]. Cyclists' position on the road can be influenced by descriptive norms which reflect a typical or normal behavior: If many other cyclists ride within the dooring zone, then the descriptive norm in this situation is to ride in the dooring zone [5]. People may also ride in the dooring zone because they are convinced that important people around them would approve of this behavior (injunctive norm), e.g. because it is communicated verbally. Apart from influencing cyclists' choice of position through norms, installing bicycle lanes with buffer zones to keep cyclists out of the dooring zone would be a solution. However, particularly in urban areas, a lack of space can make this impossible. Additionally, if tram tracks ran on the road, it is not always practical to mark bicycle lanes or protective lanes, especially when there is little space to the right of the outer tram track. In connection with frequent bicycle crashes roads with tram tracks, it is discussed whether cyclists might particularly often ride within the dooring zone there as not to have to cross the track.s [3, 6]. In those cases where marking of bicycle lanes or protective lan.es is not feasible due to width or tram track constraints, bicycle pictograms, so-called sharrows, can be marked in the middle of the lane as a measure aimed at encouraging cyclists to choose a position outside of the dooring rone and to increase their perceived safety, another factor influencing the positional choice [2]. To date, a joint experimental variation of the presence of tram tracks, parked cars, and sharrows with the aim of investigating cyclists' position on the road and their feeling of safety has not yet t.aken place. Two online studies were carried out to address this research gap, with cyclists being asked to indicate their perceived safety and their preferred position on the road based on images of a traffic situation in which the presence of tram tracks, parked cars and sharrows was varied. [From: Introduction