Cars overtaking cyclists on different urban road types – Expectations about passing safety are not aligned with observed passing distances. (August 2022)

• Record Type: Journal Article
• Authors: von Stülpnagel, Rul; Hologa, Rafael; Riach, Nils
• Is Part Of: Transportation research. Volume 89(2022)
• Page Start: 334
• Page End: 346
• Publication Date: 2022-08
• Subjects: Passing distance -- Overtaking -- Subjective safety -- Speed limits -- Cycling infrastructure; Automobile drivers -- Psychology -- Periodicals; Automobile driving -- Psychological aspects -- Periodicals; Transportation -- Psychological aspects -- Periodicals; 629.283019
• DOI: 10.1016/j.trf.2022.07.005
• Languages: English
• ISSNs: 1369-8478

Abstract

Highlights: We investigate the cars overtaking cyclists for different road types. Expectations about the passing safety are assessed in a web-based survey. We measure observed passing distances with a bike-mounted sensor. The legal minimum passing distance was kept in a third of the passing events. We find discrepancies between the expectations and the observed passing distance. Abstract: Cars overtaking cyclists have been identified as a source of crashes and subjective risk. Several studies investigated the passing distance for different road types. There has been less research concerning cyclists' expectations concerning the passing distance at different road types. Thus, we aim at contrasting cyclists' expectations about the passing safety for different speed limits and cycling infrastructures with the passing distances observed at corresponding urban road types. For this purpose, we show participants images of a predefined set of survey zones in a web-based survey, and ask them about the expected passing safety of cars overtaking them when imagining riding their bikes at these locations. We measure the observed passing distances at the same survey zones with a bike-mounted sensor. We find that cars meet the German legal minimum passing distance of 1.5 m in towns in only 30% of all observed events. In 30 km/h speed zones, passing distances at roads featuring dedicated cycling infrastructure (e.g. bike lanes, cycling boulevards) are decreased as compared to those featuring no cycling infrastructure. In contrast, people estimate that the passing safety on roads with dedicated cycling infrastructure is safer than without cycling infrastructure. This effect is even more pronounced on living streets. Situations where oncoming cars (e.g. living streets, 'opposite' roads) must be passed in close distance are apparently not perceived as particularly dangerous. Cycling tracks in 50 km/h speed zones increase both the observed passing distance and the corresponding expectations about passing safety. Taken together, the qualitative comparison of the two datasets implies that cyclists' expectations about cars passing them in a more adequate and safe distance in streets with reduced speed limits and dedicated cycling infrastructure are not justified in light of the actually observed passing distances. Possible explanations for the contradicting patterns could be that cyclists prefer situations where space is explicitly dedicated for bikes, that they account for the anticipated car traffic volume, and that they assume oncoming cars as less dangerous to pass.