Tread for heavy-goods vehicle tire

The tread has a total axial width W and a wearable thickness PMU of material and has at least four grooves on each side of a midplane that divides the tread axially into two parts. The grooves divide the tread into a middle, intermediate and edge regions 6. The middle region has an axial width Lm of at least 30% and at most 60% of the total width W. The total volume void ratio when new is less than 17%, and the middle region has a volume void ratio that is less than half the total volume void ratio. The middle region comprises a plurality of transverse sipes opening into the grooves, and the sipes have depths at least equal to 75% of the depth of the grooves. The number of transverse sipes in the middle region is greater than the number of transverse sipes on each intermediate or edge region.