That's an excellent and practical question for park planners and maintenance teams. While there's no single universal mandate, the most popular and commonly specified size for an outdoor trash can in a city park is the 32-gallon (120-liter) to 50-gallon (190-liter) capacity receptacle.
This size range strikes the ideal balance between capacity and practicality. Cans in this volume can handle a significant amount of daily waste from park visitors without becoming too heavy or cumbersome for maintenance crews to empty. You'll often see these as standalone barrels or paired units (for trash and recycling) along pathways, near benches, and around playgrounds.
The choice within this range depends on specific park zones. A 32-gallon can is frequently used in lower-traffic areas or for secondary placements. The 50-gallon can is often the workhorse for high-traffic locations like picnic areas, sports field entrances, or near food concession stands. For major gathering points or event spaces, you might see even larger 65-gallon wheeled carts or stationary dumpster-style units.
Key factors influencing the choice include foot traffic volume, collection frequency, and wildlife concerns. Durable, lidded models are essential to deter pests. Ultimately, the "most popular" size is the one that minimizes overflow between collections while optimizing the logistics and cost of park maintenance. A well-sized and well-placed system keeps parks cleaner and more enjoyable for everyone.