The diagrams illustrate the key structural and financial characteristics of two road tunnels constructed in Australian cities, including their dimensions, ground composition, construction periods, and costs.
Overall, the second tunnel required roughly double the financial investment of the first and was both longer and deeper. It also accommodated greater traffic capacity, with three lanes of vehicles compared to two in the original tunnel.
The first tunnel was built below a bridge, with the ground above it consisting of sand, whereas the second tunnel was built below a road, with stone and clay directly above. In terms of dimensions, the second tunnel was built with a considerably greater depth, being 2.5 meters, as compared to the first tunnel, with its depth of 1.5 meters, and a length of 3.6 kilometers, which is roughly 1.4 kilometers longer than the first one. It also shows a wider capacity for traffic, comprising 3 three lanes in contrast to the 2 lanes in the first tunnel.
The period of construction for the second tunnel began in 2002, lasting until 2006, which is considerably shorter than the twelve year period required for the first tunnel, which began in 1986 and finished in 1998. However, it cost about twice the amount needed to build the first tunnel, with the second costing 1.1 billion dollars and the former costing 555 million dollars.