That's a great question, and one that many city dwellers have! The short answer is no, you cannot reliably use a standard trash bag in *any* urban trash can. While it might seem like a one-size-fits-all solution, the reality is that public and private urban bins come in a surprising variety of shapes and sizes.
Think about the bins on your street corner, in a park, or even the one provided by your apartment building's janitorial service. Their dimensions are not standardized. A typical 13-gallon kitchen bag, which is what most people consider "standard," might be too tall and narrow for a short, wide public bin, causing it to slump inside or not fit at all. Conversely, it could be too small for a large, wheeled city container, leaving excess bag material that can get caught and tear when the bin is emptied.
Using the wrong size bag leads to practical problems. A bag that's too large is wasteful and can create a floppy, messy opening. A bag that's too small won't contain all the trash, potentially allowing liquids and debris to soil the inner can, which creates odors and attracts pests. The best practice is to take a quick moment to check. If it's your own bin, measure its height and circumference. For public bins, a visual estimate is your best tool. Many stores sell a variety of pack sizes, so you can find one that closely matches your most frequently used bins. A well-fitted bag ensures a cleaner, more hygienic disposal process for everyone, making our shared urban spaces more pleasant.