The diagrams provide information about two different road tunnels built in different time periods and other different features.
Overall, the later tunel is way more deeper and expensive.
The first road tunel was build in the period between 1986 and 1998. Located under the water, probably a river, the tunel is 1.5 meters deep. That also means, that the tunel has sand above it. Total cost of this project is 555 million dollars.
The constraction of the second tunel started in 2002 and was finished in 2006, which is 8 years later than when the first one was completed. Even though the construction process was 4 years, which is 2 times faster than the first tunel, the tunel is 1 meter deeper, which is 2,5 meters, however it is located not under the river, but under the road, so it has stone and clay above it. Cost of the later tunel is 1,1 billion dollars, which is two times as the first one.