This quote tells us several things: It goes back to the theme of history repeating itself: time is going in a circle. The plan for the railroad reminds Ursula of her late husband's (José Arcadio Buendía I) inventions. However, three things are noticable about that:
1. They are so far removed from modernity that they can't seperate fantastical inventions like memory machines from real things like railroads.
2. It circles back to what we said aboutthe names: JAB1 went crazy over his inventions while Aureliano Triste is very calm and organised in his approach.
3. Úrsula is always the one to figure this stuff out and see the connections