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A matter of space and perspective – Cyclists’, car drivers’, and pedestrians’ assumptions about subjective safety in shared traffic situations

von Stülpnagel, Rul / Rintelen, Heiko

Abstract

Highlights • We compare cyclists’, drivers’, & pedestrians’ assumptions about subjective safety. • Both cyclists and car drivers perceive mixed traffic as very unsafe. • On sidewalks, cyclists feel generally safe, but pedestrians do not. • Physical separation of lanes creates high safety for all road user groups. • Narrow cycling lanes next to parked cars feel safe for drivers, not for cyclists.

Abstract Subjective safety has been considered a key factor for a successful promotion of cycling. As of yet, subjective safety and the factors affecting it have been studied almost exclusively from the cyclists’ perspective. However, subjective safety is largely determined by the interaction of cyclists with other road users. We thus argue that it is crucial to assess the subjective safety different road user groups associate with shared road situations, because street designs that increase the subjective safety of one group may have negative impacts on the subjective safety of another group. For this purpose, we conducted a large-scale, web-based survey presenting computer-generated 2D images showing various traffic situations. The entire pool of images included 1,900 variations and combinations of road designs. About 21,500 individual participants provided about 460,000 estimates with regard to the safety they associated with travelling at the shown location from the perspective of cyclists, car drivers, or pedestrians. Our analysis with generalized mixed models focused on three base scenarios and the comparison of the different perspectives: Side streets were perceived as unsafe by both cyclists and car drivers. A prominent designation as a cycling boulevard had highly positive effects, especially for cyclists. On main streets, cyclists and car drivers rated mixed traffic without cycling infrastructure as very unsafe, and situations with cyclists travelling on protected bike lanes as very safe. Whereas car drivers rated all types of cycling lanes as safe, this did not generally apply to cyclists. In particular, narrow cycling lanes adjacent to parked cars felt unsafe for cyclists. We hypothesize that this discrepancy has a self-reinforcing mechanism: Research on risk-taking suggests that the low risk perception of car drivers leads to more risky behavior (e.g. overtaking cyclists with higher speed and less lateral clearance), which in turn decreases the subjective safety of cyclists. We found an inverted pattern for sidewalks, where cyclists felt mostly safe, and the more vulnerable pedestrians did not (especially if there was no clear indication of lanes for both groups). Taken together, our research sheds light on an as-of-yet rather under-researched issue: the perception of a traffic situation may vary significantly depending on the perspective and transportation mode of a road user. More specifically, our findings suggest that the subjective safety of vulnerable road users in a traffic situation can be negatively affected by the perception of this situation by the less vulnerable road users. We present recommendations about road designs that feel safe for all road user groups.