Serious collisions involving cyclists have more than doubled in a south west London borough since 2018, despite the rollout of 20mph speed limits on most of its roads.

Richmond Council said it believes the rise is linked to more people cycling in the borough, along with an increase in reporting incidents.

The council is set to investigate reducing speed limits at remaining accident hotspots, after reviewing the rollout of 20mph restrictions across roads it maintains. It estimates that 97 per cent of the roads it maintains are now restricted to 20mph due to the rollout, which was completed in 2020.

The council's transport committee agreed to investigate the rise in serious collisions and draw up plans to tackle the issue on Tuesday, September 17. Lib Dem councillor Alexander Ehmann said the overall reduction in collisions was 'encouraging', but acknowledged concerns over the drastic increase in serious collisions involving cyclists.

The committee also approved plans to explore whether 30mph roads with high collision rates should be restricted to 20mph, including parts of Staines Road and Hampton Court Road.

The report said: "The results from the collision analysis have identified positive steps overall in collision reduction. However, there remains concern over increased collision numbers around the more vulnerable road users, namely cyclists, powered two-wheelers and pedestrians.

"These ultimately tend to result in a higher severity of collision, highlighted by the rise in serious injury collisions. The increase in these user numbers is likely a key factor in addition to new methods of collision reporting."

A report by council officers revealed average speeds have reduced by 2.6mph across the borough since 2018, and by 4.4mph on roads that had average speeds of more than 24mph in 2018. It said there were 31 sites with average speeds of 24mph or more in 2020 immediately after the rollout of the 20mph speed limit, while there are now only five.

The total number of collisions on all council-maintained roads fell from an average of 338 collisions a year between 2016 and 2018 to 301 in 2021 to 2023. Despite this, collisions involving serious injury increased from an average of 53 collisions a year between 2016 and 2018 to 82 between 2021 and 2023.

The figures include a rise in serious collisions involving cyclists from an average of 20 between 2016 and 2018, to 46 between 2021 and 2023. Those involving pedestrians increased slightly from an average of 13 collisions between 2016 and 2018, to 16 between 2021 and 2023.