Delayed opening of Nantong Metro Line 2

Does the subject want to ask "Why is Nantong Metro Line 2 delayed?"? Construction schedule and safety factors.

1. Construction progress: There are many links involved in the construction of Nantong Metro Line 2, among which link delay or other problems will affect the whole project progress, thus delaying the opening time.

2. Safety factors: The construction of Nantong Metro Line 2 needs to go through strict safety review and approval procedures. During the construction process, potential safety hazards were found and needed to be rectified, which delayed the opening time.