That's a really interesting question about urban trash cans. I've actually wondered the same thing when seeing cigarette butts scattered around public bins. Making the openings smaller specifically for cigarette butts seems like a smart idea at first glance – it could prevent people from tossing larger trash items into dedicated cigarette disposal spots and might encourage more deliberate disposal.
However, from what I've observed in city planning discussions, there are some practical considerations. If openings become too small, they might get clogged easily or discourage use altogether. Some cities have experimented with adding separate, narrow metal receptacles right on top of trash cans specifically for cigarettes. These often have a small opening just for butts and sometimes sand inside to safely extinguish them.
The real challenge isn't just the opening size, but providing convenient alternatives. Smokers often won't go out of their way to find proper disposal. That's why you see more integrated designs now – regular trash openings alongside dedicated cigarette slots. The best solutions I've seen combine slightly smaller openings with clear signage and strategic placement near building entrances and seating areas.
What's your experience with this? Have you noticed particular designs that seem to work better than others in your area?