1. When the height of the bridge is 50 and 100, there are 6 connecting holes at each end, and when the height is 150 and 200, there are 12 connecting holes at each end.

2. Support spacing: The support spacing should be less than or equal to the load curve allowable load and support span.

3. The width of the cable tray: When selecting the width of the cable tray, a certain amount of spare space should be reserved to add cables for the future.

4. Separate laying: When there are few power cables and control cables, they can be installed on the same cable tray, but the power cables and control cables must be laid separately with a partition in the middle.

5. Cable fixing: When the junction bridge is laid horizontally, the connection between the bridges should be set at 1/4 of the span as much as possible. Cables running horizontally are fixed every 2 meters or so, and cables running vertically are fixed every 1.5 meters or so.