Tolkien wasn't a great fan of industrialization, as we can see from his descriptions of both Isengard and the Shire thanks to Saruman's meddling.
It's not clear how he envisaged the time between the events of LotR and the modern day, though. He briefly sketched out a sequel, which was to take place after Aragorn's death in the time of his son, Eldarion, when Men were already beginning to turn back to evil, but he abandoned it early on.
We do know that he considered the time of the Elves to be passing, and Men would inherit. Saruman says as much, according to Gandalf, when he originally tried to subvert him:
'The Elder Days are gone. The Middle Days are passing. The Younger Days are beginning. The time of the Elves is over, but our time is at hand: the world of Men, which we must rule.'
But perhaps the best clue to how Tolkien thought of the future comes in the conversation between Gimli and Legolas when they first enter Minas Tirith:
'It is ever so with the things that Men begin: there is a frost in Spring, or a blight in Summer, and they fail of their promise.'
'Yet seldom do they fail of their seed,' said Legolas. 'And that will lie in the dust and rot to spring up again in times and places unlooked-for. The deeds of Men will outlast us, Gimli.'
'And yet come to naught in the end but might-have-beens, I guess,' said the Dwarf.
'To that the Elves know not the answer,' said Legolas.