The car skidded on the ice and ran into the guard rail on the side of the bridge.

rail 是名词，指"栏杆、横杆"，通常由金属或木材制成，用于防护或支撑。 guard rail 指安装在道路或桥梁边缘的防护栏杆，用于防止车辆或行人跌落。