EDIT: Turns out Dr Andy Palmer left his role as CEO of Aston Martin a couple of years back. In his time since leaving the company, he joined electric bus maker Switch mobility as CEO, before stepping down from that role too at the end of last year.
Let's start with these comments from Dr Andy Palmer...
The former CEO of Aston Martin and COO of Nissan who is, Wikipedia tells me, referred to as the 'Godfather of EVs' due to his work launching the Nissan Leaf. Palmer took to Twitter, sorry, let's try that again. Palmer took to X. Nah, Palmer took to Twitter to recall his train strike experience...
"Drove into London today (anticipating a train strike) to be met with 20mph speed limits throughout Central London, policed with hundreds of speed cameras," he said. "Another erosion of car users' rights which along with ULEZ is likely to be unpopular with voters. I guess the argument for is lower emissions and crash injuries, but I doubt there is credible research behind this.
> James May says 20mph is "plenty fast enough", and hopes "change in attitude" can help end road sectarianism
"20mph should be reserved for around schools & hospitals where it's entirely valid. Emissions in the streets of London will almost certainly higher since one drives in a lower gear to control momentum avoiding the speed cameras. And at 20mph, I'm now swarmed by bicycles overtaking from all angles raising the risk of collision. I'd love to see the research that supports this but like so many things these days, I doubt it's supported by valid facts but rather political expedience."
Cue replies from people unpicking every single word, sharing studies and data to the contrary and just generally making Dr Palmer go very quiet on the matter...
Of the replies linking the research and data that Dr Palmer suggested "like so many things these days, I doubt it's supported by valid facts but rather political expedience", one reply shared the link to a British Medical Journal study from 2020 titled: 'Twenty miles per hour speed zones reduce the danger to pedestrians and cyclists'.
Another popular one was Transport for London's February release stating that "new data shows significant improvements in road safety in London since introduction of 20mph speed limits".
"At sites monitored on the Transport for London Road Network (TLRN), collisions involving a vulnerable road user have decreased by 36 per cent, while collisions resulting in death or serious injury have decreased by 25 per cent after speed limits were lowered," TfL concluded.
On the emissions front, research by Imperial College, cited by TfL and in this Welsh government literature review into the state of evidence on 20mph speed limits, found that "it would be incorrect to assume a 20mph speed restriction would be detrimental to ambient local air quality".
The review suggested: "Although there was a moderate increase in CO2 and NOx in petrol cars, the study reported that particulate matter emissions reduced for both petrol and diesel cars and NOx and CO2 emissions reduced for diesel cars. As road traffic is responsible for up to 80 per cent of particulate pollution, this was a significant finding which supports the case for measures which secure observance of 20 mph speed limits."