by Four more years of Sadiq Khan’s London – as voters have just chosen – means four more years of ideology before evidence. The Mayor’s “Vision Zero” plan commits the city to a set of policies to end all traffic deaths and serious injuries – a feat unmatched by any city in the world.
And we are only beginning to see what it looks like for London to implement such a comprehensive, utopian vision. Ulez, low-traffic neighbourhoods, road closures, and just recently, a new wave of 20mph zones on the Transport for London Road Network (TLRN).
Appearing, in his acceptance speech, Khan described London as “warning now” on “climate action” which he demanded, “clean up our air”. Except that there is no evidence that Khan’s pet policies, including 20mph, have any effect on air quality.
20mph is one of the biggest changes to London’s road system in years – certainly since 30mph limits were introduced in 1936. But few people in local government or City Hall, The Telegraph which showed that they prevented the cost-benefit analysis for the policy from being properly evaluated.
Eight of the 11 boroughs that introduced general 20mph limits admitted they have no record of carrying out a formal cost-benefit analysis and the others could provide little detail about their analysis – which mainly looks at costs applied once, not for a long time. -term impact.
When Tory MP Ranil Jayawardena MP asked the Minister for roads and local transport, Guy Opperman, if the Government knew more, he was told that they had not “assessed the impact of the cost on the economy of 20mph speed limits in London. .”
This is a scandal. Wide 20mph limits now cover around half the capital, but there has been little debate across the city about them. The public knows if they are making us poorer.
One TfL document suggests that Khan is rushing to introduce new 20mph limits on the main arterial roads for the TLRN by March next year as he “wants to publicize the program before the pre-election period before the next Mayoral election “.
Also of note, it also asserts that lower speed limits will not affect journey times and therefore only need to be considered as one-off implementation costs. But the “final impact” section of the economic section is marked “TO BE COMPLETED”.
In Wales, the Labor government then disagreed. they did carried out an economic impact assessment that assumed (slightly) longer journey times, leading them to calculate a negative net value of £4.5 billion to the Welsh economy over 30 years.
Since London’s economy is much worse than Wales, the economic damage could be even greater. However, traffic moves more unpredictably in urban areas, so it may be less. We do not know, because proper research has not been done.
The TfL document may also underestimate implementation costs. An “option” is only considered when “no changes are made to the physical infrastructure”. Other options, including new signage and changes to road markings, are “out of scope”. The measures don’t take into account the wider economic impact of lost trade, lost journey time, longer running cars, slower deliveries, slower buses and the cost to the police implement this sometime.
The 11 boroughs I asked for had a largely similar approach to SF applications. Conveniently, they see 20mph limits as purely a safety issue and press for behavioral change. As a document by Lambeth’s Cabinet Member for Environment & Sustainability claimed, 20mph limits are a “cost-effective way of reducing collisions. [and] encouraging more sustainable modes of travel…”
The Advertising Standards Authority concluded last year that Khan had made “misleading” claims about the Ulez expansion and its impact on air quality. This came just months later The Telegraph he revealed that Khan’s office had tried to discredit and “silence” scientists who found that his ultra-low emission zone (Ulez) policy had little effect on pollution.
TfL does not make the same mistake with 20mph, admitting that there will be no “net benefit” to air quality and most councils also admit that there is no evidence that air quality will improve (when the country hilly range and/or roads used by larger vehicles, evidence shows that 20mph can worsen air quality).
So, all that’s really left is safety. In fact, TfL says safety is the “primary objective” of all-20mph limits. But what does the evidence say?
In their “Narrative Business Case” report on 20mph limits, TfL points to a 2009 report on German data collected between 1999 and 2007. The same study is used in the “Vision Zero” report to claim, “if a pedestrian is hit by a vehicle at 20mph, they are about five times less likely to be killed than if they were hit at 30mph.” But they do not clarify that these are only initial impacts, and that the study compares 50km/h with 40km/h.
Curiously, 15-year-old foreign data takes precedence over 2018 research specifically commissioned by the Department for Transport (DfT) as “the largest, most comprehensive and sophisticated study of the effects of 20mph speed limits. made in the UK”.
It concluded that “there is insufficient evidence to conclude that collisions and casualties have changed significantly following the introduction of 20mph limits in residential areas.” This conclusion will not be well received by those desperate to impose restrictive measures which could, in the end, drive us off the roads.
Perhaps that is why the Mayor of London and local government have not yet commissioned a comprehensive cost-benefit analysis of the city’s 20mph limits – because it may not give them the answer they want.
