That's an excellent question that many city planners and facility managers consider when selecting waste containers. From my experience observing municipal installations, both materials have distinct durability profiles.
Plastic urban trash cans, typically made from polyethylene, offer impressive corrosion resistance. They won't rust when exposed to rain, snow, or de-icing salts—a significant advantage in coastal or snowy regions. Modern rotational-molded plastic bins maintain flexibility in freezing temperatures where metal might become brittle. However, prolonged UV exposure can cause fading and potential weakening over 5-10 years, though UV-stabilized formulations have improved this dramatically.
Metal trash cans, usually galvanized steel or aluminum, provide superior structural rigidity. They're less prone to deformation from impacts or overfilling. Powder-coated finishes enhance corrosion resistance, but scratched areas remain vulnerable. In high-vandalism areas, metal often withstands abuse better, though denting can be permanent.
The real durability difference emerges in maintenance. Plastic requires virtually none beyond cleaning, while metal needs touch-up painting and rust prevention. Weight matters too—plastic's lighter weight reduces stress on mounting hardware but makes it more prone to tipping in windy areas.
For most urban settings, high-density polyethylene bins now last 7-12 years, comparable to metal's 10-15 year range when both receive proper care. The choice ultimately depends on your specific climate, budget for replacement versus maintenance, and aesthetic requirements. Many cities now use hybrid approaches: plastic for general public areas, metal for high-traffic commercial zones where structural integrity is paramount.