I'm not a game dev but I always felt like that was kind of the point of water hazard? Okay yes the railroading could have been better but for me the point of the chapter is that it's just kind of barren, and you're travelling all this way and this is what it is like for Gordon. I feel like it adds to the atmosphere, and I am willing to bet when the writers wrote the story, it wasn't just "Gordon goes to the resistance base and fights a helicopter on the way", I think it makes sense to write at length about how alone he (and you) is with his thoughts, and it gives you time to think about lore. Up until now, you have been bombarded with lore and info and action, if you're a hl1 player your mind is racing to fill in the voids between the games (why is Breen in such a high position? What the fuck is happening?) And Water hazard is a long corridor designed to let you think about that more than it is a vehicle section. On the flip side, car levels in episode 2 and lost coast have much more of this "go there" feeling because they don't decompress much of anything.