River guardrails, also known as bridge guardrails, refer to guardrails installed on bridges. Its purpose is to prevent out of control vehicles from crossing the bridge, and it has the function of preventing vehicles from breaking through, underpassing, and climbing over the bridge, as well as beautifying the bridge building.

There are many methods for classifying bridge guardrails. In addition to their installation locations, they can also be classified based on structural features, collision resistance, and other factors. According to the installation location, it can be divided into bridge side guardrails, bridge central divider guardrails, and guardrails at pedestrian and lane boundaries; According to structural features, it can be divided into beam column (metal and concrete) guardrails, reinforced concrete wall type expanded guardrails, and composite guardrails; According to the anti-collision performance, it can be divided into rigid guardrails, semi-rigid guardrails, and flexible guardrails. The common forms of guardrails include concrete guardrails, corrugated beam guardrails, and cable guardrails.