That's a fantastic question, and it's at the heart of effective urban sanitation. The goal isn't just to have cans; it's to have them where people naturally need and use them. My core advice centers on behavioral observation and strategic convenience.
First, conduct a "litter audit." Walk the streets and note where litter accumulates—near bus stops, fast-food outlets, park benches, and transit station exits. These are prime candidate spots. Placement should be intuitive; a person shouldn't have to deviate from their path.
Visibility is non-negotiable. Place bins in clear sightlines, well-lit at night, and never hidden behind obstacles. Think about the "30-foot rule": if someone can see a bin within about 30 feet, they're more likely to use it.
Proximity to "generation points" is critical. This includes food vendors, convenience stores, public transport queues, and recreational areas. A can should be within a few steps of where a product is consumed.
Finally, consider capacity and maintenance. A single, overflowing bin is worse than none. In high-traffic zones, use multiple or larger-capacity bins and pair placement with a reliable collection schedule. The cleanest cities place bins where the need is, not just where it's administratively easy. It's about designing for human behavior.