The place I drop off my recycling has large dumpsters with slits about 4" high for cardboard. Clearly it's to try to force people to actually break their boxes down, but it still fails. I've seen people taking more time cramming an unbroken cardboard box through one of the openings than it would have taken to just break the damn thing down.
I
hate breaking boxes down, but I still don't understand people doing that. I break them all down at home so they don't take up as much space between drop offs. That lets me get more recycling in the back of my van as well.
They also replaced one of the large dumpsters for plastic with one that has a grid over the openings. That forces people to not toss a whole bag in. Usually the other one is full, but the grid one isn't even half full.