> What indication do you have that the construction time for tunnel 3 is due to corruption or even that it's taking longer than necessary?

These two questions are casually put next to each other in the same sentence but they're incredibly different. Personally, I don't think that corruption is a significant factor in how long it took. The second question is way too leading/framed - "necessary" doesn't exist past the physical limits.

For example, would the same project have taken the same time in China? No. Does that mean it should've taken as long as it would've in China, as clearly it took longer "than necessary"? Not by definition.