A 20-mph speed limit has been brought in on many major routes in central London. For example it covers the main east-west route of Millbank, Victoria Embankment, Upper and Lower Thames Street, and Tower Hill. Most drivers think such limits are ludicrous and are not justified by the demands of road safety although average traffic speeds on these roads are often less than 20 particularly after the spread of cycle superhighways caused more congestion. But not all roads in London are so congested or justify a 20 limit at all times of the day.
You can go to this web site for an explanation as to why 20 mph signed-only speed limits are unjustifiable on any rational basis: www.20sSenseless.org
But will 20 be the limit in future or will the attack on all forms of vehicle traffic be extended until we are all driving at walking pace? There are certainly some people in power in London who seem to think that the only way to cut accidents is to stop traffic altogether or make it drive at a snail’s pace. It is certainly the case that TfL plan to extend the 20 limit to other major roads across the capital in “Phase 2” of their Safer Speeds proposals.
But the City of London Corporation is going a step further already. They are going to ask for Ministerial approval to impose a 15-mph limit across the Square Mile to replace the existing 20 mph limit. The City has had a 20-mph limit since July 2014. Has it made any difference to casualty numbers? Not obviously so as you can see from the chart below taken from this City Corporation report published in 2018: https://tinyurl.com/vvt58d9 . Pedestrian casualties have actually been rising and other transport mode users have probably fallen simple because there is now less traffic in the City due to concerted efforts to discourage it. In summary there is no good evidence that a 20 limit has worked to reduce road casualties in the City of London, or anywhere else either.
The City Corporation has to get permission from the Secretary of State for Transport to impose a 15 MPH limit for which there is no approved signage for example and enforcement is also doubtful. Anyone who thinks that 15 mph is ludicrous should write to: Rt Hon Grant Shapps MP at Department for Transport, Great Minster House, 33 Horseferry Road, London SW1P 4DR or use the form on this contact page: https://forms.dft.gov.uk/contact-dft-and-agencies/
What limit will be chosen when 15 MPH does not work? 10 or even 5? When will this lunacy end?
You may be sure that it won’t end in just London