That's an excellent and very practical question. The short answer is yes, the signage on urban trash cans absolutely can and should be changed if recycling rules are updated. It's not just possible; it's a critical part of making the new rules work.
Think of trash can signage as the direct communication link between the city's policy and the person holding a piece of waste. If the rules change but the signs don't, it creates immediate public confusion, leads to contamination of recycling streams, and ultimately causes the new program to fail. For example, if a city starts accepting pizza boxes for recycling but the bins still say "No Greasy Cardboard," people will throw them in the trash.
The process involves coordination between the public works department, sustainability offices, and often the city's budget team. Changing signage is a logistical project. It requires designing new, clear labels (often using universal icons and multiple languages), manufacturing them, and deploying crews to update thousands of bins across the city. This can be done gradually as bins are serviced or through a dedicated campaign. The cost is a factor, but it's considered a necessary investment for the success of the waste management program.
Many forward-thinking cities now use modular or adhesive signage that is easier and cheaper to replace. Some are even piloting digital labels or QR codes that can be updated remotely for dynamic information. So, while updating physical signs takes effort and planning, it is a standard and essential practice for adapting to evolving sustainability goals and ensuring public participation. Clear signs are the key to turning policy into practice on the sidewalk.