San Francisco isn't uniformly dense and narrow, but it does have both, and it's run remarkably well so far.
Anyway, we'll see how the London rollout goes, but I get the impression London's got a lot more of those kinds of roads.
That is extremely narrow, I wonder why the city has not designated it as a one-way street? They've done that for other similarly narrow sections of the same street farther north.
The trick to UK streets is that parking actually happens on the street itself, and when driving you must find a spot when people are not parking to make way for people coming the other way.