The player can travel them by using the three ways of traveling through the sectors that the tube, trucks and boats (in the sewers only).
The player can travel them by (in the sewers only). The player is using the three ways of traveling through the sectors that the tube (in the sewers only). The player is using the three ways of traveling through the sectors that trucks (in the sewers only). The player is using the three ways of traveling through the sectors that boats (in the sewers only).