Yes, for most people, a street bench with a curved back will feel noticeably better after 30 minutes or more. The reason is simple: your spine is not flat. A straight back forces your lower back to bridge the gap between your pelvis and shoulder blades, which can tire the lumbar area and encourage slouching. A gentle curve fills that gap and supports the natural inward curve of the lower back, so your muscles do not have to work as hard to hold you upright.
That said, the exact shape matters more than the word “curved.” A bench with a subtle, well-placed lumbar curve is usually excellent. A bench with a very deep curve can push your shoulders forward and feel worse than a plain straight back. The best public benches tend to have a mild recline, a curve that matches the lower back, and a seat depth that lets different users sit without pressure behind the knees.
For long periods, comfort also depends on the whole setup. A curved back helps, but if the seat is too hard, too shallow, too deep, or angled wrong, you will still shift around. Armrests help you change position and stand up more easily. Material matters too: metal gets hot and cold, while wood is usually more neutral.
So if you are choosing or designing a bench for long sitting, prioritize a gentle lumbar curve rather than an aggressive scoop. Test it for ten minutes in your normal sitting posture. If you feel support in the small of your back and no pressure between your shoulder blades, it is likely to be more comfortable than a straight-back bench over a long period.