Yes—mostly. Center armrest benches are one of the most recognizable examples of hostile architecture, sometimes called anti-homeless benches. Their basic function is to break up the long flat surface that would otherwise let someone stretch out. If you try lying across one, the armrest presses into your back, hips, or ribs. For most adults, that makes full-length lying uncomfortable enough to give up quickly.
But does it truly prevent lying down? Not completely. A center armrest doesn’t make the bench impossible to lie on; it just makes it much less comfortable. Someone can still curl up on one side, especially if they are shorter, flexible, or willing to bend their knees. Others might sit sideways or drape their legs over the edge. What the armrest really does is stop the most common behavior: stretching out flat across the entire bench for a long sleep.
From a public seating design perspective, that is often the exact goal. City officials and business owners may want the bench to remain available for sitting while discouraging long-term sleeping or camping in busy areas. Supporters say this keeps public benches usable for more people. Critics say it is a targeted anti-homeless design that removes one of the few places where a person without housing can rest. The debate is less about whether it works and more about whether it is humane.
So, in real-world terms: yes, street benches with a center armrest do prevent most people from lying across them. They are not a perfect physical barrier, but they create enough discomfort and awkwardness that most people won’t bother. Whether that counts as thoughtful public space design or cruel urban furniture depends on your view of what a bench should be.