Where’s the evidence? Dulwich cycling study over-inflated

Where’s the evidence? Dulwich cycling study over-inflated, produced by the Dulwich Alliance, questions the findings of a study published in December 2020 by academic Dr Anna Goodman, which makes a direct correlation between the closure of Calton Avenue in June 2020 and an increase in the number of cyclists.

Like all the groups in the Dulwich Alliance, One Dulwich shares Dr Goodman’s desire to find ways to make walking and cycling easier, particularly for children cycling to school, but believes there are far better ways of doing this than closing the junction 24/7. 

In Dr Goodman’s original study, volunteers counted cyclists in Dulwich on a single road, on a single morning, in November 2020.  Dr Goodman then compared the figures with historic cycle counts from 2018 and 2019, and an unreliable modelled estimate based on 2011 figures, to suggest that the increase in cycling was directly related to the road closure. But the study failed to mention all the other reasons why cycling might have increased – reasons that pre-dated the road closure – including the effect of Covid-19 and the lockdowns, the major remodelling of the two junctions at either end of the road, the introduction of Quietway 7, and cycling-friendly initiatives like bike storage introduced by local schools. 

Even more importantly, the study failed to consider whether different interventions, like cycle lanes or a School Street, might have produced the same or better results – a particularly crucial omission given that the 24/7 closure has displaced traffic on to other local roads like Croxted Road, East Dulwich Grove and Lordship Lane, increasing congestion and pollution for local children walking or cycling to school. Although Dr Goodman doesn’t mention this in her study, her charts suggest that 93% of the children she recorded cycling to school on Calton Avenue were travelling between 7.45am and 8.45am. This means that a School Street-style timed closure – which would have a far less detrimental impact on the wider community – would have virtually the same benefits as the current 24/7 closure. 

The Dulwich Alliance’s review of Dr Goodman’s study was the subject of an article in the South London Press on 5 March (see page 13).