Pneumatic radial tire tread for high-speed running vehicles

In a pneumatic radial tire for high-speed running vehicles having a directional tread pattern defined by arranging one or two relatively wide circumferential grooves in only a central region of a tread and plural slant grooves acutely crossing with the meridian of the tire and extending substantially in parallel to each other in a convergent direction toward the equator of the tire in each of side regions of the tread, and a ratio of maximum height of the tire section measured from bead base to maximum tire width of not more than 0.8, the improvement wherein the slant grooves are arranged in a herringbone form with respect to the equator without communicating with the circumferential groove, each of which extending from an initial end separated from the adjoining circumferential groove to a terminal end opening sidewards at each side edge of the tread and being a folded line at a folding point corresponding to 0.3-0.45 times of the tread width as positioned from the equator of the tire that an inclination angle .alpha. of line segment inward from the folding point is 40.degree.-85.degree. with respect to the meridian of the tire and an inclination angle .beta. of line segment outward from the folding point is smaller than the inclination angle .alpha. and 0.degree.-50.degree. with respect to the meridian of the tire.