The article mentions that Atlanta runs sweeps quarterly. This is only inside the city though. I live outside the city (25 to 90 minutes depending on traffic) and we don't get any sweeping. The intersection outside our neighborhood gets about an accident a week and it's just constantly filled with glass and, occasionally, bumpers. The tow truck drivers are normally kind enough to sweep it to the side but that isn't great for cyclists. Everyone drives SUVs here and their tires are big enough that glass doesn't matter so no one is going to agree to pay for sweepers.
And that's just off to the side, it'll accumulate and / or spread from there.
When I visited the US and its highways, I was surprised to see how much things like exploded truck tires were littering the sides of the road.
Drive in the south in the summertime and the "road gators" (truck tire remnants) are often in the middle of travel lanes.
Doesn't solve the problem, just pushes the stuff into the curbs where it then is a concentrated threat to bike tires. What they should do is mount a big electromagnet on the back of the sweeper to then pick any metal up.
The sweepers I'm familiar with sweep the debris under the machine and then into a holding space. Does that not work with this kind of debris?
Street sweepers actually do pick up the debris, not just deposit it in the gutter. At least here in Atlanta they do.