[heipei]

Here in Germany they have deployed so-called "whisper/porous asphalt" on the highways leading into some major city centres. Since it's more porous than regular asphalt it absorbs noise (and rain) much better, but the drawback is that it's more expensive to manufacture and is less durable.

Just saying that there are probably lots of different noise reduction techniques that all add up their percentages, but these will only be put in place if noise pollution is taken as serious as it needs to be.

[coredog64]

My (US) state DOT paved over the concrete highways with rubberized asphalt for similar reasons. The asphalt doesn’t last as long, but it’s quieter and cheaper than concrete repairs. It’s also something that uses up old tires.

[kolinko]

Yeah, rubberized asphalt is pretty much standard in Europe, and it's awesome :) The stuff in Germany parent mentioned is next gen even quieter.

[jankotek]

It releases nano particles, not great for breathing.