> By building this project [CrossRail], London is just catching up to its peers. Paris has had a similar system, the five-line RER, since the 1970s. Berlin’s S-Bahn predates World War II.

I think I lived in London when CrossRail a just an expensive glint in the government's eye. I didn't know that it was an S-Bahn thing. I guess it makes sense, as London always was the city with the most famous of U-Bahns but no real S-Bahn.

Now I live in Sydney, a city that has always had an S-Bahn (of course we don't call it that) but know U-Bahn. But just a few days ago the Sydney Metro (https://en.wikipedia.org/wiki/Sydney_Metro) was opened.

So it seems like the combined approach is what big cities converge on. Although the Sydney metro doesn't even go into the centre of the city, so it's not really equivalent.

Or that S-Bahns were some kind of new technology.

I find it interesting that