That's a fantastic question, and one that urban planners and designers think about a lot. The short answer is yes, absolutely. The design of the opening on a public trash can plays a huge role in whether litter ends up inside it or scattered around the base.
Often, the problem is a simple gap or a small, round hole. People might miss, or wind can blow lightweight trash back out. A more thoughtful design can guide behavior. For instance, a wider, funnel-shaped opening is more inviting and easier to aim for. Angled openings or flaps that close partially can help contain odors and prevent wind from pulling trash out, while still being easy to use.
Some of the most effective designs consider the "last inch" of the disposal process. An opening that is clearly marked, at a comfortable height, and paired with a design that signals "this is where trash goes" psychologically encourages proper use. When it's easy and intuitive, people are more likely to do it right. So, while no single fix solves all littering, a well-designed opening is a crucial first step in keeping our sidewalks and parks cleaner.