From January 2018 all new taxis had to be zero-emission capable (ZEC), with an official CO2 emissions figure of no more than 50 g/km, and a minimum zero-tailpipe emission range of 30 miles.

You're not allowed to have a taxi older than 15 years.

That's great to hear, I have to admit it's over a year since I was last in London.

That said, the odds of getting run over by a black cab were already quite high so hopefully they're not totally silent. ;)

When I picture a black cab I don’t picture it actually moving, their traditional role is surely to line the streets or sit in traffic with the engine running, decorating the air with particulates.

Also allow wealthy (usually white male) businessmen to beat the traffic by clogging bus lanes.

There are also a few electric-only buses rolling out. Along with a lot of them being hybrid with auto start-stop now so they aren't polluting while in traffic. Id like to see more of them move to electric only though!