That's an excellent and practical question! From my experience working with urban planners and public works departments, the scratch and dent resistance of modern public trash cans is a major focus for manufacturers. The short answer is: they are surprisingly resilient, but it depends heavily on the materials and construction.
Most high-quality urban bins are now made from heavy-gauge stainless steel, often type 304 or 316 for corrosion resistance. These are not the thin metals of the past. The steel sheets are formed and welded to create a rigid structure that can absorb impact without permanent deformation. For scratch resistance, a textured or brushed finish is almost always used. This isn't just for looks; it cleverly disguises everyday scuffs and minor abrasions from bikes, shopping carts, or general city wear-and-tear. You'll notice most scratches simply blend into the pattern.
A key technology is powder coating. This is a thick, baked-on polymer finish applied to carbon steel bins. It creates an incredibly hard shell that is far more resistant to chipping and scratching than old-fashioned paint. Deep gouges are rare, and the coating also prevents rust if the underlying metal is exposed.
For dents, the design philosophy has shifted. Instead of thin, hollow shells, many bins now have reinforced corners, ribbed sides, or double-walled construction in impact-prone zones. Think of it like a car's crumple zone—it's designed to withstand a knock. While a direct, forceful hit from a vehicle will damage any bin, everyday bumps from people or debris cause little to no visible effect.
So, while no public fixture is completely indestructible, today's urban trash cans are engineered to look good for years with minimal maintenance. Their resistance to scratches and dents is a testament to improved materials science and a better understanding of the harsh realities of city life. You can expect them to remain functional and aesthetically pleasing despite constant use.