Abstract: A tire tread for a truck tire, especially of radial ply construction and designed for use on well-made roads, comprising a small number of zig-zag grooves. The sidewalls of each groove are each provided with a supporting buttress of varying height or width such that the maximum support is provided at or adjacent the points where the groove projects into the surrounding tread rubber. The provision of such a buttress provides a varying degree of support for each groove sidewall along the length of the groove and assists in preventing uneven wear of the tread rubber and reduces damage caused by stones trapped in the groove.