A snow tire tread having a plurality of blocks separated by grooves and provided with sipe incisions dividing into several parts from a certain depth onwards, (complex sipes each having, when viewed in cross section, a rectilinear first part extending radially from the tread surface of the tread, and a second part extending the first part and comprising at least two branches each having an end. The tread has cavities each extending between the branches of a complex sipe and having a bottom situated at the same level as the ends of the branches. The cavities and the grooves of the tread are configured so that this tread has a voids surface ratio at the end of wear greater than or equal to 35%. Furthermore, the distance (D) between two branches of two adjacent complex sipes is at least equal to 2 mm.