Are you talking about the "drop downs" where you can pass in only one direction? Mostly it's a device to keep you from getting too far away from where the plot is taking taking place, but they also use it the start of the game to prevent you from wandering back to your truck. You're also blocked from reaching certain areas too soon or from leaving the game map. Is what you're talking about actually preventing you from advancing the plot? Sometimes the game forces you to take different paths coming from and returning to the tower. but that's on purpose and you're supposed to figure out both paths.

probably it's what you mention but there are certain roads that I somehow did take which was in the "advanced plot" and I was unable to come back. And another example was in the cave where I did go with the plot but was unable to move around probably cuz of certain rocks and the climbing rope that we used to climb down. Had to restart a bunch of times in order to progress but somehow finished the game