A tire includes a tread band provided with a tread pattern including a first and a second portion of tread pattern, repeated just the same along the circumferential extent of the tire, forming respectively a short pitch module and a long pitch module of the tread pattern, wherein the modules include a respective first transverse groove in which, starting from an axially outer first end thereof toward an opposed axially inner second end thereof, an initial section and a section of enlarged cross-section are formed, the latter being blind, at least on its axially inner side, when in the footprint area. The initial section and the section of enlarged cross-section have, respectively, a first width and a second width, and the ratio between the second width and the first width of a first transverse groove belonging to a short pitch module is greater than the ratio between the second width and the first width of a first transverse groove belonging to a long pitch module.