👉 A sub tunnel is a type of underground infrastructure that connects two or more underground systems, such as cities and highways. It typically consists of a single tunnel with multiple entrances and exits for traffic flow. Subtunnels are designed to reduce the amount of land required for construction and can be used in areas where there is limited space. In some cases, sub tunnels may be constructed using specialized technology or materials that allow them to pass through difficult terrain or obstacles. These tunnels can also have multiple entrances and
