That sounds awful. I used to manage a factory in Ruabon & know the area well , often driving up from Bucks in various Mogs and staying at the Lion Quays in winter & the wine Bar in Llangollen in summer.
That blanket 20 limit will surely raise NOX levels etc as most cars aren't designed for that.

I have driven Belle for her MOT today, the tester owns a 5l Mustang so he was delighted . I've driven just over 8k miles this year down slightly on last which was 9k. .

JohnV6
2022 CX Plus Four
2025 MG ZS EV aka Trigger