How good are American roads?

I heard a civil engineer make a claim once that the dust on the side of the road is about 300% more laden with precious metals like platinum, than random mining. I suppose this is all roads and not just American roads, though.

Isn’t it supposed to be mostly brake pads, rotors, and tire rubber?

Would be fascinating to imagine it being economically viable to vacuum up and reprocess it, but based on the above I’ve assumed it was worthless.

Sounds a bit like the guys that collect the sludge from the sewers in jewellery and gold smithing districts in cities, then pan it for gold. Its not going to make anyone rich, but theres enough gold dust in there to buy some food and shoes for somebody hungry enough to dive into a sewer and collect sludge!

Supermarkets that make you put in a quarter to take a shopping cart are really just paying the homeless $0.25 each to return them from the parking lot.