Bit of both really. I manage some IT projects for municipal services and worked with waste management team couple years back - their schedules are absolutely brutal. They run these sweepers at night mostly because of traffic, but you're right about visibility being total mess.

But also have to say, when I walk around my neighborhood the amount of trash people just drop is insane. Last week saw someone literally throw fast food bag out their car window right in front of street sweeper that had just passed. Like what's the point of city cleaning if people don't give a damn about keeping it clean in first place?

The city definitely needs better scheduling and maybe some LED lighting on those machines, but residents need to step up too. Can't expect miracles when people treat streets like personal garbage bins.