highway bridge section 3d model

A simple low‑poly section of a straight elevated highway in Japan, at night. One flat rectangular road plane with dark asphalt material and clearly visible white lane markings running along the length. On both sides of the road, add continuous metal guardrails with vertical posts. The road should be quite long in one direction and narrow in the other, like a typical 2‑lane expressway, but completely empty with no cars or people. The surface should be mostly matte, not shiny, and the model should be clean and simple, suitable for use in a Unity game.