A new 15 mph speed restriction for the City of London has been prohibited by the Department of Transport on the grounds that it is technically impossible due to inaccurate speedometers.
In May of 2019, the City of London Corporation announced intentions to restrict speed limits within the Square Mile to protect pedestrians and bicycles from accidents and reduce pollution.
To support their effort to establish the 15 mph speed limit, the corporation commissioned an evaluation of the proposal’s safety benefits. They discovered that the probability of death in a collision with a vehicle moving 20 to 25 mph was between 10 and 20 percent. This decreases to between 2 and 5 percent between 10 and 15 miles per hour.
The City of London Corporation desired to implement a 15 mph speed limit on all roads under its jurisdiction within the Square Mile.
The government has prevented the City of London from implementing a 15 mph speed limit throughout its authority.
The concept entailed imposing a blanket 15 mph speed limit on all City of London Corporation-controlled roadways within the Square Mile.
The Department of Transportation stated that it would be difficult to police the new reduced speed limit and highlighted that not all vehicles are equipped with speedometers that are marked every 5 mph.
According to the Independent, despite government opposition, the corporation intends to erect ‘advisory’ 15 mph speed limit signs along the highways under its supervision.
However, they will not be permitted to utilize the standard speed limit sign consisting of a circle with black letters on a white background bordered by a red band.
At the time of the plan’s release, AA president Edmund King stated that reducing the speed limit from 20mph to 15mph is “unlikely to make much of a difference” because traffic in the Square Mile has “moved no faster than a horse-drawn carriage for the past century.”
He said, “All road users and pedestrians being more vigilant, obeying the rules of the road, and putting away their phones would likely be more beneficial than lowering the speed limit.”