Magnets incorporated into a traditional street-sweeping truck shouldn't be bothered by street fixtures, unlike a on a bicycle. I can see how the bicycle approa

Magnets incorporated into a traditional street-sweeping truck shouldn't be bothered by street fixtures, unlike a on a bicycle. I can see how the bicycle approach might experience challenges, but even there I think the problem isn't particularly severe. Switchable electromagnets which could automatically sense a large ferrous object (e.g., grates, covers) and deactivate or reduce strength over them might be another option. A filtered reply to my earlier comment argues that electromagnets are "massive with generators". This ... is seriously misguided. Electromagnets can be tiny, you'll find them in small motors (electric toothbrush, the haptic vibrator in your mobile device). Given extant electric capabilities of a streetsweeper, a modest grid/array of magnets would be trivial to implement.