First of all, the reduction in traffic numbers on the High Road is similar to that for cars, a drop of 23% between 2002 and 2018, from 19k to 15k. Improved public transport may well have contributed partly to that fall, but as far as that has occurred it indicates that those vehicle trips can indeed be substituted, and are therefore not unavoidable. The increase in cycle counts I gave is taken from TfL's manually collected annual series, not the camera counts. However, the 2021 manual data agrees well with the camera counts for hours monitored on 10/11 June last year: the manual count was 2889 while the sum of the S62 cycle lane and S62 eastbound roadway at a similar location comes to 2753, less than a 5% difference. I've excluded the westbound roadway bike counts because, as you mention, there is an issue with this camera picking up a portion of the bikes in the cycle-lane. Hence including them leads to an overestimate of the proportion of bikes in the roadway. Using just the cycle lane and eastbound roadway numbers, 83% of the cycle counts came from the cycle lane.The vehicle counts using both the east and westbound roadway cameras come to just over 8k, a drop to 42% of the 2002 levels, while car counts have fallen even lower to 35% of 2002 levels. Because of the more than doubling of bike counts, bike numbers reached over 50% those of cars in June last year and peaked at 54% in September. The increase in cycling on the High Road is exceptional on a London-wide basis. Between 2019 and 2021, Chiswick High Road has seen the largest increase in bike counts of any of the 450 Outer London locations monitored by TfL. Also in the top ten was Boston Manor Road. It's unlikely to be coincidental that both of these roads provide segregated cycle lanes. As I said, the observed shifts in travel mode along the High Road already demonstrate that a much higher proportion of vehicle trips than your estimate of 17% are avoidable. Once there is a clear run from the High Road to Hammersmith Road, we might even see bike counts overtake car counts along stretches of C9.
Tom Pike ● 1578d