PURPOSE: To lower the noise to be made by tires during the traveling, by changing the numbers of basic pitches of groove walls of grooves in a tread design having three grooves basically thereby modulating the frequencies.

CONSTITUTION: In a tire having a tread design with main three grooves, each of the grooves is formed in a zigzag pattern and has 50W90 pitches over the circumference of the tire 1. When the groove walls of the grooves are numbered 1W6 from the left, with respect to at least one combination of the grooves 1 and 2, 3 and 4, and 5 and 6 the numbers of the pitches or the arrangements of the pitches are differentiated. At least one groove is formed to be straight. According to this arrangement, the amplitude of the modulation of the frequency of the tire can be increased, the acoustic pressure level can be lowered due to the interference of the sound, and the noise due to the traveling sound of the tire can be lowered.