In the US we frequently use a neutral on distribution lines which connect individual customers. The variety of single-phase loads on distribution lines makes it difficult to balance the load across all phases without using a neutral to carry the unbalanced load. Transmission lines, however, are always balanced since they are never used for single-phase loads. Because of this, our transmission lines typically do not have a neutral, tho they may have a grounded shield wire above the phase wires for lightning protection.
