The given diagram briefly illustrates two underground pipeline systems in two cities in Australia.
Overall, it gives information about the start and completion time, budget, lane capacity, and the general description of the structure of these two types of underground roads.
As can be observed in the diagram, tunnel A was built earlier as it began construction in 1987 and was completed in 1992. Its total cost was estimated to be around 556 million US dollars. In addition, Tunnel A functions to connect two sides of the city, which are separated by a large river. It is under the river, lined with a thick layer of construction materials consisting of stone and sand. This tunnel is approximately 2.2 kilometers long and 25 meters high, and has a capacity of two lanes on each side.
Evidently, tunnel B was constructed later, from 2004 to 2007. The total cost of tunnel B is twice that of tunnel A, around 1.1 billion US dollars. Moreover, Tunnel B appears to be a secondary road located beneath a large canal or a major tunnel, running parallel to the main road on the surface of the city. Its length and height are significantly greater than the first tunnel mentioned, respectively 3.6 kilometers and 35 meters, with the lane capacity also increased to 3 lanes on each side.