The ornamental design for a tire tread, as shown and described.
FIG. 1 is a perspective view of a tire tread showing my new design, it being understood that the tread pattern repeats circumferentially throughout the outer circumference and shoulder of a tire, the opposite side perspective view being identical thereto;
FIG. 2 is a full front elevation view of the tire tread thereof of FIG. 1;
FIG. 3 is a side elevation view of the tire tread thereof of FIG. 1; and,
FIG. 4 is the other side elevation view of the tire tread thereof of FIG. 1.
In the drawings, the broken lines defining the sidewall, inner bead and the peripheral boundary between the claimed tire tread and the unclaimed sidewall depict environmental subject matter that forms no part of the claimed design.