Directional tire tread having a rolling surface, this tread being provided with a plurality of incisions bounded by mutually opposing walls, each of said walls entering the rolling surface in such a way as to form an edge called the leading edge of an element of material, corresponding to the edge that enters the contact patch first, and an edge called the trailing edge of the same element of material, corresponding to the edge that enters the contact patch after the leading edge, each incision comprising at least one segment bounded by mutually opposing walls that make, with a direction perpendicular to the rolling surface passing through the intersection of the incision with the rolling surface, a negative average angle α whose absolute value is less than 55°, this tread being characterized in that this segment of negative angle α exits the rolling surface via an enlarged end portion bounded by mutually opposing first and second faces, the angles of the first face and second face being positive and not equal to each other.