Abstract: The procedure for the construction of underground transport infrastructures, comprises the steps of: excavating an underground transport tunnel comprising a first pipe and a second pipe substantially parallel to one another; making a bypass tunnel connecting the first pipe and the second pipe which comprises the sub-steps of: introducing a launching chamber along the first pipe up to a first predefined position chosen along the longitudinal direction of the first pipe, the launching chamber being able to launch a tunnel boring machine; introducing an arrival chamber along the second pipe up to a second predefined position chosen along the longitudinal direction of the second pipe, the arrival chamber being able to receive the tunnel boring machine; excavating the bypass tunnel making the tunnel boring machine move forward from the launching chamber to the arrival chamber along a direction transversal to the first pipe and to the second pipe.