Truck tire tread and truck tire

The invention provides for a heavy truck tire tread (2) having a longitudinal direction, a lateral direction and a thickness direction, said tread having a ground-engaging contact surface (CS) and having a main longitudinal center groove (5), two main longitudinal shoulder grooves (3, 7) and two main longitudinal intermediate grooves (4, 6), said five main longitudinal grooves defining six main longitudinal ribs (8, 9, 10, 11, 12, 13), said five main longitudinal grooves comprising one hidden groove, two open grooves and two partially hidden grooves; wherein each of said two partially hidden grooves comprises openings (41, 61) to the ground-engaging contact surface and undersurface channels (42, 62) connecting adjacent openings, longitudinal sipes (43, 63) extending substantially along the longitudinal direction and connecting successive openings to the respective channel; and wherein said hidden groove (5) comprises an undersurface duct (52), a longitudinal sipe (53) extending substantially along the longitudinal direction and connecting said undersurface duct to the ground-engaging contact surface, said hidden groove being the main longitudinal center groove of the tread.