[ExI] puzzler

[Adrian Tymes]

On Sat, Jan 13, 2018 at 6:21 PM, William Flynn Wallace
<foozler83 at gmail.com> wrote:
> Here's one you can get your psychological teeth into:
>
> When England’s Bath and North East Somerset Council, at a cost of 871,000
> pounds (US$1.18 million), lowered the speed limit to 20 mph in 13
> high-accident zones, it made a difference, and quickly: in the first year,
> fatalities and serious injuries due to traffic increased significantly.

Why was England marking something in miles per hour instead of
kilometers per hour?