| 摘要 |
The two pairs (1,2) of tunnel tubes (1',1",2',2") extend mutually parallel and run mutually at right angles. The pairs arranged at same depth underneath conurbation, enclose square parallelepiped (4) of natural earth, at intersection portion of pairs. The earth is removed from hatched area (6) along outer sides (5) of roads carrying traffic along direction (3) running past parallelepiped, to form circular roundabout arrangement. Independent claims are also included for the following: (1) road tunnel arrangement production method; and (2) road tunnel network. |
