The maps compare two projects for two separate car-only subterranean tunnel systems in two Australian cities.
Overall, there are many differences between the two tunnel systems, which are about cost, length, depth, and time of construction. The first tunnel also took much longer than the second tunnel about time of building. However, the first tunnel cost to construct approximately half as much as the second tunnel.
The first tunnel, which was constructed between 1986 and 1998, cost $555 million and was built underneath a bridge and had a structure under a layer of sand. Meanwhile, the second tunnel only took four years to complete but cost twice as much, at $1.1 billion, which was constructed beneath a layer of stone and clay, and above the tunnel is a bustling urban area.
The two tunnels varied significantly in both depth and length: the first tunnel was 1.5 meters high and 2.2 kilometers long, while the second tunnel was 2.5 meters high and 3.6 kilometers long. Additionally, the first tunnel system had four lanes, whereas the second tunnel system accommodated six lanes.