Contraflows and cycling safety: evidence from 22 years of data involving 508 one-way streets

Organisation: University of Leeds

Date of Publication: November 2022

Uploaded to Knowledge Centre: 30 November 2022

This research suggests that contraflow cycling on one-way streets is a low cost intervention that can improve the cycling experience and increase participation.

Evidence from several studies suggest that cyclists on contraflows have a lower crash risk. However, implementing contraflow cycling is often controversial, including in the United Kingdom. This paper examines whether contraflow cycling on one-way streets alters crash or casualty rates for pedal cyclists.

Focusing on inner London boroughs between 1998 and 2019, the researchers identified 508 road segments where contraflow cycling was introduced on one-way streets. They then identified road traffic crashes occurring within 10m of these segments and labelled them as pre-contraflow, contraflow or contraflow removed crashes. They then calculated rates using the number of crashes or casualties divided by the time exposed and generated 95% confidence intervals using bootstrap resampling. These rates were then adjusted for changes in cordon cycling volume and injury severity reporting.

There were 1,498 crashes involving pedal cyclists: 788 pre-contraflow, 703 contraflow and seven following contraflow removal. There was no change in adjusted overall pedal cyclist crash or casualty rates when contraflow cycling was introduced. Proximity to a junction doubled the crash rate. The crash rate when pedal cyclists were travelling contraflow was the same as those travelling with flow.

The study finds no evidence that introducing contraflow cycling increases the crash or casualty rate for pedal cyclists. It is possible that such rates may indeed fall when contraflow cycling is introduced if more accurate spatio-temporal cycling volume data was available.

The researchers recommend all one-way streets are evaluated for contraflow cycling but encourage judicious junction design and recommend UK legislative change for mandatory-two-way cycling on one-way streets unless exceptional circumstances exist.

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