Computer optimized noise barriers are a thing, https://en.wikipedia.org/wiki/Sound_baffle#Highway_noise_barriers https://en.wikipedia.org/wiki/Sound_baffle#High

Computer optimized noise barriers are a thing, https://en.wikipedia.org/wiki/Sound_baffle#Highway_noise_barriers https://en.wikipedia.org/wiki/Sound_baffle#Highway_noise_bar... Common freeway walls are cast concrete preforms, so it's easy to make them have a particular geometry. In terms of protecting the surrounding community from the noise, the wall tops actually have a lot more impact than the wall geometry itself due to edge diffraction.