Completely relevant. It’s all that remains of the train tracks today. Grinding out the last drops from those sunk costs, attracting minimal investment to keep it minimally viable.
Grinding out returns from a sunk cost of a century-old investment is pretty impressive all by itself.
Very few people want to invest more: the private sector doesn't want to because they'll never see the return, the governments don't want to because the returns are spread over their great-great-grandchildren's lives and that doesn't get them re-elected in the next n<=5 (because this isn't just a USA problem) years.
Even the German government dragged its feet over rail investment, but they're finally embarrassed enough by the network problems to invest in all the things.
