Honestly, there’s no single magic number, but for a typical city block I’d start with about three public trash cans. That usually means one near each corner and one mid-block if the block is long or busy. In practical planning terms, that’s roughly one can every 150–200 feet of street frontage, adjusted for local conditions.
If the block is mostly low-density residential, one or two cans may be enough. If it has a subway entrance, bus stop, food trucks, convenience stores, or a park, you’ll probably need four to six and more frequent emptying. Downtown commercial blocks with heavy foot traffic can justify even more. A good rule for urban trash can placement is to put public waste bins where people naturally pause or finish a snack: corners, transit stops, crosswalks, and storefront clusters.
Don’t forget maintenance. Too few city block trash cans causes litter; too many poorly serviced cans become a nuisance. Good street litter planning is about capacity and collection frequency, not just count. The real target is enough trash can density to keep the sidewalk clean without overflowing. So for most typical blocks, 2–4 cans is sensible, with 3 as a solid baseline and adjustments based on foot traffic, land use, and collection frequency.