The meaning of this sentence was: There were no roads in the world, but people kept walking on them, and the roads gradually developed. Similarly, the roads in the world that were originally free of traffic jam became more and more congested as the number of vehicles increased. This sentence reflected that the development and progress of human society was the result of people's constant actions and creativity. It also reminds us that we need to be cautious and patient in the process of creating and developing new things to avoid unnecessary problems and difficulties.