The diagrams compare two road tunnels, Tunnel A and Tunnel B, in terms of their design, construction timelines, costs, and dimensions in an Australian city.
Overall, while both tunnels serve similar purposes and share the same basic design, Tunnel B is larger, deeper, and considerably more expensive than Tunnel A, reflecting advancements in infrastructure development over time.
Tunnel A, constructed between 1987 and 1992, spans 2.2 kilometers beneath a riverbed composed of stone and sand. Its depth is 25 meters, and it features a twin-tube structure to accommodate vehicles. The total cost of building this tunnel was $556 million. This tunnel is relatively shorter and shallower, making it a less expensive project compared to Tunnel B.
On the other hand, Tunnel B, completed much later between 2004 and 2007, is significantly longer at 3.6 kilometers and extends 35 meters underground. Its structure also includes twin tubes designed for vehicular traffic. However, the project incurred a much higher cost of $1.1 billion, likely due to its greater length, depth, and more modern engineering requirements.