That's an excellent and often overlooked question! Getting the spacing right between recycling and trash bins is crucial for effective waste management in public areas. The best practice isn't about a single fixed measurement, but a set of principles centered on user behavior and clarity.
The golden rule is proximity with distinction. Bins should be placed side-by-side, typically with a gap of no more than 1-3 feet (30-90 cm) between them. This "arm's reach" distance is key. If bins are too far apart, people will often default to using the nearest one, regardless of the stream. Placing them as a paired unit forces a conscious choice.
However, physical spacing is just one part. Clear visual distinction is equally important. Use consistent, high-contrast colors and universally understood icons (not just text) on each bin. The lids themselves should be different colors or shapes (e.g., blue for recycling, black for trash, with corresponding hole shapes). This creates a "sorting station" feel.
Consider the flow of foot traffic. Place the pair directly in the natural pedestrian path—near exits, in food court seating areas, or along major walkways. The trash bin should usually be positioned on the more natural "dominant" side (e.g., to the right in right-hand traffic countries), as it remains the most frequently used.
For high-volume areas, using a single, multi-stream receptacle with separate, labeled openings is often the most space-efficient and effective solution. This eliminates the spacing question entirely by integrating the choice into one unit.
Ultimately, the goal is to make the right choice the easy choice. Close proximity reduces laziness, while clear signage reduces confusion. This combination significantly increases capture rates for recyclables and reduces contamination, making the system work better for everyone.