Funny thing is Typhoon Lagoon, Aquatica are all near roads. As you mentioned so was WNW . Been to all and cant remember hearing traffic noise. Obviously those side roads and a 4 lane highway arent the same granted but still, sound velocity plays a major role here. The more plants, running water, splashing, other park noises, background music, and peoples voices, the better for keeping sound out. A Sound wall would be great but might rob the thematic look of Volcano Bay.