| Topic: | Re:Re:Re:Re:Re:Re:Re:Increased casualties at Chiswick Lane | |
| Posted by: | Tom Pike | |
| Date/Time: | 27/11/24 12:05:00 |
| Francis, having dug out my post, I thought it worth comparing what we've seen on C9 to Schepers predictions in his 2011 paper. C9 as originally designed (give or take the replacement of wands with kerbing) has since January 2023 delivered the junction setback and platforms on the High Road, and we now have 17 months of collision data to compare with 36 months from 2017 to 2019. From 2020 to 2022 there was the pandemic and various temporary versions of C9 that didn't offer all the mitigation. In the 2017 to 2019 period there were 12 cyclist collision injuries over 36 months, with an average survey ridership of 2200. From January 2023 to May 2024 there were 2 cyclist collision injuries over 17 months, with an average survey ridership of 3371. Hence the collision risk to cyclists is now reduced to just 23% of the risk prior to C9. C9 has actually outperformed Schepers prediction of 47%, halving his predicted risk! Obviously 2 is a low number of collisions and subject to sampling error, but we'd expect to have seen 9 collisions if the risk had been unaffected by C9, and 2 is a statistically significant reduction in comparison - there's a less than 1% probability of seeing such a low number of collisions if the rate was unchanged. So at least on C9 on the High Road, we can state unequivocally that after C9 was fully installed we have seen a significant improvement in cyclist safety. This result can be compared to C9 on King St, and specifically at Weltje and Rivercourt roads, where the mitigations have not been implemented and the increased risk is evident. |