Actually railroads were built largely by a few determined wealthy families.
No one today would,build their own metro because fixed track systems are extremely inflexible and maintenance intensive. Govt today would prevent people building theirown metro anyway, so its a moot point.
Todays “metro” for people are cars and motorbikes, and people build cars and bikes regularly.
People,build private roads. Govt,would,prevent people building their own public roads, so its a moot point.
People have built their own private airfields. They are not sized for jumbo jets, but people have and do build their own airfields. If a person would go ahead and attempt to build a large public commercial airport on their property as Obama is referring to, govt would step in and prevent tis from appening. So again, a moot point.
Of course, the wealthy financiers of railroads were “lucky”, from Obama’s estimation. As were the financiers and builders of canals before railroad technology.
The original “metro” subterranean railroads were built by private companies too. But in the case of NYC particularly, the city insisted on putting out the funds, ostensibly claiming that the costs of such construction would have been too high for any private company, but more for the purpose of control; hence the subsequent fare controls imposed on the private companies who did the building, operation and maintenance. The city also never followed through on the promise of allowing the use of subway tracks at night for freight haulage.