This is a cool chart, but I wonder how someone could normalize this data for the size of a country, or how many miles are between its major metropoles, or something. China's a lot bigger than most of the other countries on this list, and the HSR is concentrated in the heavily populated eastern half of the country.
It'd be hard to quantify, but I'm sure some statistics person could compare transportation methods, that includes speed, distance, energy usage, population, capacity, and probably a few more, per capita.
You could isolate it to a country's top X biggest cities, and how traveling between them compares in all those metrics.
This is a cool chart, but I wonder how someone could normalize this data for the size of a country, or how many miles are between its major metropoles, or something. China's a lot bigger than most of the other countries on this list, and the HSR is concentrated in the heavily populated eastern half of the country.
It'd be hard to quantify, but I'm sure some statistics person could compare transportation methods, that includes speed, distance, energy usage, population, capacity, and probably a few more, per capita.
You could isolate it to a country's top X biggest cities, and how traveling between them compares in all those metrics.