You can really see the Paris-centric approach in France: From Paris you can reach almost any other major city in 4h, but on the other hand, all the other metropolis can barely reach 1/4th of the other major population center in 4h.
Compare this to Germany where almost any major metropolis can reach 80% of the country in 4h ...
Compare this to Germany where almost any major metropolis can reach 80% of the country in 4h ...