Michael,You wrote: “Your claims about cycle casualties involved nothing more than looking at dots on a map and guessing. A proper analysis using source police collision reports showed just how wildly inaccurate your guesses were.”I produced a simplistic amateur assessment to raise awareness of the safety problems with two-way cycle tracks, which seemed little known by many people promoting CS9. I made it clear it was a simplistic assessment and that the authorities should produce a professional quantitative risk assessment, which they still have not done.Your analysis included some helpful further analysis of police collision data, but was also an amateur assessment with very selective use of data and overly optimistic assumptions:- Data from a single Dutch study, assuming Dutch conditions were directly transferable to Chiswick. The Netherlands are a special case, showing much better results than other countries: their extra risk factor for junctions on two-way tracks over one-way tracks is around 1.75. Studies in Sweden and Finland, where cycling levels are lower and closer to UK levels, show risk factors of 10 and 12, which explains why they largely stopped using two-way tracks over 20 years ago. The Dutch study states Dutch figures are unlikely to be transferable to other countries. In my assessment I used a mean average from several countries.- Your study used a risk factor that assumed the cycle track was set back 2-5 metres at every side road junction – at most junctions it was not and a significantly higher risk factor should have been used. Let alone now that there are no set backs or raised platforms.- Your conclusion that CS9 would reduce cyclist injuries by 75% doesn’t pass a sense check. The most successful road safety measure in recent decades were 20 mph Zones (with traffic calming) which reduced injuries by up to 70%. It is highly improbable then that a measure that is known to be dangerous and warned against in all design guidance such as two-way tracks could produce a better result! One-way tracks are known to be significantly safer, so what would you expect those to produce – 100%?! Too good to be true I’m afraid.- Your study only considered the side roads issue and not all the other (non-junction) factors and pedestrian collision data that lead to two-way tracks not being recommended on streets such as the High Road.- European studies also warn against relying only on police collision data for studies of cycling safety. Studies that also include hospital admission data show the majority of cyclist injuries are not reported to the police. This is particularly applicable to bicycle-bicycle and single bicycle collisions that increase with two-way tracks. So I have to disagree with your claim that this was somehow a “proper” and conclusive study, and that my simplistic assessment led to “wildly inaccurate guesses”. In fact if you include the factors listed above, my estimate of three to four times current collision levels is about right.You wrote: “You also opposed the cycle lane on Boston Manor Rd which has been in operation for about 18 months now…. Your prophesies of doom about cyclist casualties there simply haven’t happened.”My opposition here wasn’t so much on safety grounds as that is was a wasted opportunity to introduce something that could not be extended beyond this half mile stretch of road. Ealing Council said they would not extend the route on their section of the road as a two-way track, so there was little prospect of this being more than an isolated link of little use to anyone other than GSK staff going half a mile to Boston Manor tube.It’s worth remembering that significant increases in people cycling occur where NETWORKS of cycle routes are introduced. Isolated lengths of cycle route rarely make much difference.And at Boston Manor there were only two side road junctions, which Hounslow Council agreed to re-design to be safer. Having said that, when I last looked at the police collision data, the cyclist injuries had moved from the road junctions to the side road junctions on the cycle track. The number of injuries had increased significantly over the previous three years before the track was built. So again, not a great advert for the safety benefits of two-way tracks, even where there are few side roads.I hope Hounslow Cycling will be warning local cyclists of the dangers of two-way cycle tracks on roads such as the High Road, which are not obviously apparent? Probably safer to avoid using CW9 eastbound, although the narrowed traffic lanes now make the road quite unpleasant too!
Stephen Donnelly ● 2195d