The given diagram briefly illustrates two underground pipeline systems in two Australian cities.
Overall, it gives information about the start and completion times, 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 its construction began in 1987 and was completed in 1992. Its total cost was estimated to be around 556 million US dollars. In addition, Tunnel A serves 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 was 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, at 3.6 kilometers and 35 meters, are significantly greater than those of the first tunnel mentioned, with the lane capacity also increased to three lanes on each side.