Routing Structure

These indicate the location of key structures related to the highway network. These may be:
Barriers: Structures or equipment constructed to control, obstruct, or prevent passage or access
Bridges and Tunnels
Crossings and Signals: Equipment such as traffic signals, and locations that control the flow of traffic

这些指示了与高速公路网络相关的关键结构的位置。具体可能包括：
障碍物：为控制、阻碍或防止通行或进入而建造的结构或设备
桥梁和隧道
交叉点和信号：如交通信号灯等控制交通流动的设备和地点。