That's a great and very practical question! Yes, many modern cities are increasingly installing public trash bins that come with built-in or attached ashtrays on top. You'll often see these in high-traffic areas like outside office buildings, near public transport hubs, in parks, and on busy shopping streets.
The design is pretty straightforward: the main compartment is for general waste, and on the lid or the side, there's a small, often metallic, cup or tray specifically for cigarette butts. The main goal is to reduce litter. Cigarette butts are one of the most commonly littered items worldwide, and they can be a fire hazard if tossed into a bin full of paper. A dedicated ashtray helps contain them safely.
From my observation, these combo units are becoming more common as part of broader street furniture upgrades. They encourage responsible disposal and make cleanup easier for maintenance crews. So next time you're walking downtown, take a look—you might spot one of these handy bins designed to keep our sidewalks cleaner.