The diagrams compare two road tunnels, labelled A and B, in terms of their structure, dimensions, construction period and cost.
In general, Tunnel B is significantly longer, deeper and more expensive than Tunnel A, although it was completed in a shorter period. Both tunnels share a similar twin-tube design.
In detail, Tunnel A, which was constructed between 1987 and 1992, has a total length of 2.2 kilometres and reaches a depth of 25 metres below the surface. The project cost approximately $556 million. It consists of two separate tubes that allow traffic to flow in both directions.
By contrast, Tunnel B is larger in every aspect. Built between 2004 and 2007, it extends for 3.6 kilometres and goes as deep as 35 metres underground. Despite taking only three years to complete, it required a much higher investment of $1.1 billion, nearly double the cost of Tunnel A. Like its predecessor, Tunnel B also features a twin-tube structure designed for vehicle transportation.