That's an excellent and practical question! The direct answer is: it depends entirely on the specific bench design. Most traditional urban benches you encounter in parks, bus stops, and plazas have fixed backs. Their design prioritizes durability, vandal resistance, and low maintenance, offering a standard upright or slightly angled position for short sits.
However, the world of urban furniture is evolving. You can increasingly find modern public benches with adjustable or multi-position backs. These are often seen in more curated spaces like university quads, upscale waterfront developments, or public libraries. The adjustment might be a simple, manual latch allowing you to set the back into 2-3 different angles. This feature caters to a desire for greater comfort, allowing people to recline slightly to read, relax, or simply enjoy the sun.
Why aren't all benches adjustable? Primarily for cost and resilience. Fixed benches are simpler, harder to break, and require almost no upkeep. Adjustable mechanisms add expense and potential points of failure. So, while the technology exists, its application is selective.
If you're seeking a more reclined public seating experience, look for contemporary design-focused installations or specific "relaxation zones" within a park. Your best bet is to scout the area—sometimes a simple walk will reveal that one perfect, reclinable bench for your moment of leisure.