Where are the 20 mph zones they promised?

Someone posted us this video complaining that it shows a car driver unable to think ahead, because the driver overtook a bicycle aggressively on the way into Montpelier, whereas everyone knows that you only put your foot down on the way out. The tax-dodger not only ended up being held up by the Audi YY03YGM, they had to drop down Brook Hill, sprintg along Upper Cheltenham Place and then squeeze past the car on Picton Street blocking the road with the hazard lights on, while the Audi was still stuck on York Road negotiating rights of way with whatever was coming from the other direction.

We feel that the whole incident documents a more fundamental problem. The 20 mph zone isn't delivering what was promised.

The opening sequence shows how a bicycle doing 18 mph held up the car, but as soon as they go a little above 20 mph to get past them, there's another oncoming bicycle before the blind zig-zags. Even the bicycle video documents the other problems: the pedestrian and their dog on Brook Hill, the two bicycles on Upper Cheltenham Place, the two kids playing with a Pogo Stick in the road -our road- at 1:14, and then another bicycle. At least the car with the hazard lights on has paid for the right to be there.

Where are the 20 mph zones? The signs show them, but the car would have been lucky to have an average speed of 10 mph across the entire journey. We were promised 20 mph limits, yet it only takes one or two people walking, cycling or even pogo-sticking around and you brought screeching to a halt. We have been betrayed.