Great question! It really depends on the type of urban bench you are looking at, but in short: most modern urban benches are designed with safety and comfort in mind, so they are not purely slick. Here is the breakdown.
Many outdoor benches, especially those made of metal or painted wood, do incorporate a textured surface. For example, powder-coated metal benches often have a slightly rough or matte finish, which helps provide grip when the bench is wet or if you are wearing smooth clothing. This subtle texture prevents you from sliding off when you sit down or stand up. In some high-end designs, you will even find a light sand-like texture embedded in the coating.
On the other hand, some concrete or polished stone benches can feel very smooth and even slick to the touch. These are often used in modern architectural settings where aesthetics are prioritized over grip. However, even these benches usually have a sealed but slightly porous finish to avoid being dangerously slippery when it rains.
For wooden benches, the texture depends on the wood grain and the sealant used. Unpainted wood (like teak or cedar) naturally has a gentle grain that offers decent friction. But if a bench is coated with a high-gloss varnish, it can feel quite smooth and slick, especially when wet.
My personal advice? If you are choosing a bench for a high-traffic or rainy area, look for a design with a "grip strip" or a built-in textured pattern. Many park benches now feature small raised ridges on the seat edges or a textured insertion. Always test the surface with your hand before sitting—if it feels too smooth, it probably is. In general, manufacturers prioritize safety, so the majority of urban benches you find today will have at least a moderate level of texture for grip. Just avoid the highly polished, decorative ones meant for indoor or dry climates.