If it goes in front, it'd either have to not have a pivot or the steering would need to be drastically changed.

Could it work like one of these front-loader tricycles? https://www.worksmancycles.com/frontload.html

Yeah, that looks like it would work. That's the kind of thing that I meant by a drastic change to the steering as that's now got two wheels at the front.

That would be cool.

Otherwise, sweepers will need both extra robust tires and to be ready change flats.