> So then the wider gauge is helpful to increase lateral stability (to prevent tipping over) since the cars are so light. If they didn't wanted to reinvent the

> So then the wider gauge is helpful to increase lateral stability (to prevent tipping over) since the cars are so light. If they didn't wanted to reinvent the wheel, they could have adopted another standard railway track gauge: the Iberian gauge https://en.wikipedia.org/wiki/Iberian-gauge_railways https://en.wikipedia.org/wiki/Iberian-gauge_railways There's a fun story about BART: the US decided to go with a blank slate approach to railway design by hiring not railway engineers but aerospace engineers, and consequently the project relied heavily on reinventing the wheel. This track gauge thing happens to be one of many examples. As BART decided to forego any standard way of doing mundane railway tracks, they had to endure decade-long delays and huge budget overruns to cover up their loss. Otherwise there would be nothing to talk about a mundane rapid transit system which already covers pretty much the whole Europe.