Tire for a heavy duty vehicle with improved grip

A tire () for a trailer of a heavy-duty vehicle having a tread (), which has at least one complex circumferential cut () in a median portion () having a first family of transverse cuts, referred to as transverse through-sipes (), having a thickness (E) at most equal to 0.8 mm, a depth (P) at least equal to 20% of the maximum depth-of-cut (H), and being at a distance (D), from the nearest external cavity (), at least equal to 7 mm, and/or a second family of transverse cuts, referred to as blind transverse cuts (), that stop near an external cavity (), that have a thickness (E) at least equal to 1 mm, a depth (P) at most equal to 20% of the maximum depth-of-cut (H), and being at a distance (D), from said external cavity (), at least equal to 3 mm.