The present invention relates to a tire designed to be fitted on the driving axles of a motor vehicle for medium or heavy load. This tire is provided with a tread comprising a plurality of full-depth transverse grooves and four circumferential series of inclined grooves and four circumferential series of inclined incisions which delimit five circumferential rows of blocks, namely two axially outer rows, two intermediate rows, and one central row lying essentially across the equatorial plane.Each transverse groove extends across the whole width of the tread, and consists of a central portion, located between a pair of consecutive blocks of the central row, and a pair of lateral portions, located between pairs of consecutive blocks of the intermediate and shoulder rows.The two lateral portions of each transverse groove are staggered circumferentially with respect to each other and penetrate into the body of the central row of blocks. The central portion of the transverse groove has a depth of 3 mm, while the depth of the incisions located between the shoulder blocks and the intermediate blocks is less than the depth of the inclined incisions located between the intermediate blocks and the central blocks.