These signs are definitely an Edgewater phenomenon. There was another one to the east at Kenmore and Glenlake. Easy to forget that litter louts don't take a day off in the winter. Snow may be on the ground but...... hiding under the surface waiting for the slowed down water molecules to warm up and evaporate is a months worth of garbage.
Quite a few corners in Rogers Park could use these reminders and a couple of garbage cans. Ward 49 has a spring clean up which has been a tradition for years. As more and more people take care of their community's litter on a daily basis such events will seem quaint and out of date. We shouldn't wait until early April to pick up a winter's worth of trash on the parkway.