Funny sequitur: years ago, companies started announcing porous aspalt products, but apparently nobody uses them. I don't know why not - cost, maintenance, durability; there could be any number of reasons why we don't see more roads using these.

Anyway, when you see demos, it's a bit mind blowing. You dump a bunch of water onto it, and it just... soaks away, leaving the asphalt looking dry.

If porous asphalt were used everywhere, that sign wouldn't be quite so dumb.

Here's a longer demonstration; the installation certainly looks more involved than repavings I've seen, driving by, but I'm no expert.