That's a really interesting and practical question! It's a common issue in urban design—how to make public furniture serve its intended purpose without inviting unintended use. The short answer is yes, absolutely. Public waste bins can be, and often are, designed to subtly discourage people from sitting on them. The key is to do it in a way that maintains accessibility for use and doesn't create a hostile public environment.
The most common and effective method is through form and shape. Designers might incorporate a rounded, sloping, or slightly angled top surface. This makes the bin inherently unstable and uncomfortable as a seat. A flat, wide lid is an invitation; a curved one is a polite deterrent. Another approach is to integrate the bin into a taller, narrower column-like structure, removing the broad, bench-like platform altogether.
Materials and details also play a role. Using materials that are thermally reactive—like metal that gets very hot in the sun or very cold in winter—can naturally discourage prolonged contact. Some designs incorporate small, subtle protrusions or ridges on the lid that aren't sharp or dangerous but are simply uncomfortable to sit on for more than a moment.
It's important to note that the goal isn't to be punitive. The best designs address the "sittability" issue while prioritizing the bin's primary functions: easy waste disposal and efficient servicing. Features like clear, wide openings and easy-access panels for cleaners are not compromised.
Ultimately, this design philosophy ties into a broader concept called "Hostile Architecture" or, more neutrally, "Defensive Design." The ethical aim should be gentle discouragement, not exclusion. A well-designed anti-sitting bin works hand-in-hand with providing ample, comfortable, and dedicated public seating nearby. The solution isn't just to make bins unusable as seats, but to ensure people have better, more pleasant alternatives to choose from.