The illustrations compare two road tunnels in two Australian cities, built in two different periods (from 1986-1998 and 2002-2006)
As observed, although the two tunnels look somewhat similar, they serve different purposes, with one connecting two banks of a water body and the other working as an underground road. The costs and times vary for the construction of these tunnels.
Looking at the shapes, the 1986-2002 tunnel is curved and the 2002-2006 is a normal underground road. Furthermore, the former is drilled beneath layers of sand while the latter is drilled through layers of stone and clay. Also, the parametres of these two tunnels show differences as the curved one is 1.5 metres high and 2.2 kilometres long. The other tunnel, otherwise, is 2.5 metres in height and 3.6 kilometres in length.
Turning to the cutaways of these two tunnels, two entrances are seen in the design of the curved tunnel while the other is a 3-lane tunnel. It took 12 years for the construction of the curved tunnel and the cost was $555 million. In contrast, the building time needed for the second tunnel was 3 times shorter relative to that of the curved tunnel, with a nearly doubled cost ($ 1.1 billion).