The pictures illustrate underground tunnel models of two Australian cities designed for automobiles.
Overall, these two systems don’t have that much common features, except for the type of transportation and the size of cars going through the tunnels.
The first tunnel system is built between 1986 and 1998 with the budget of 555 million dollars. Unlike the first model, second tunnel system is built just in 4 years starting from 2002. While the capacity of the previous tunnel is 2 cars, the second tunnel is able to have 3 vehicles at one time. It’s worth to mention that the spared budget for the second model is nearly two-fold of the first one.
Talking about the sizes of the systems, the first model is smaller than the second one in both height and width, being 1.5 meters to 2.2 kilometers, when the second tunnel system is built with 2.5 meters height and 3.6 kilometers width. Additionally, the first model is built under the water and the surface of the tunnel is covered by the sand, whereas the second system is covered by stones and clay and the top of the system is main transportation road.