My wife built the street sweeper tonight and it's both cute, quaint and to my surprise had some functionality!
The front sweepers (blue gears) are connected via non friction pins at the front center which means the outside edges of the gears drop with gravity enough to touch the ground surface and functionaly rotate when the vehicle is pushed. The side brushes function similarly. I guess I didn't expect that in a value-priced set and it's cool seeing all four going at once.
I was surprised the tires were the smooth racing-slick type and not treaded. I haven't tested other tires but maybe there's a difference in height and they need the slicks to help the side brushes touch the ground so they could function.
It's kind of a mash-up vehicle in that it is a combo recycling truck, too. Where I live recycling cans are blue and trash cans vary. City- provided are green, otherwise whatever you find sold at the local hardware store. They include a green trash can and a banana (which is more compost.. that's a kind of recycle, right?) Imaginations can be forgiving so all-in-all nothing to really complain about there.
The 1x4 bricks one each side with the recycle grqphics are printed for those that want to part out or start/add to a recycling center MOC.
Overall a neat small build and nice addition to most anyone's Lego city.