Heavy duty pneumatic tire

A heavy duty pneumatic tire comprising:

• a tread that comes into contact with a road surface;
• a pair of sidewalls connected to the tread;
• a belt located radially inward of the tread;
• and a pair of cushion layers located radially inward of axially outer ends of the belt, wherein
• each end of the belt is stacked on a corresponding cushion layer of the pair of cushion layers,
• at least four circumferential grooves are formed on the tread, thereby forming at least five land portions aligned in an axial direction, and, among these land portions, a land portion located on an equator plane or at the equator plane side is a center land portion, land portions located at outermost sides in the axial direction are shoulder land portions, and land portions located between the center land portion and the shoulder land portions are middle land portions,
• the belt includes a plurality of layers stacked in a radial direction, and, among these layers, a layer having a largest width in the axial direction is a first reference layer, and a layer stacked at an outer side of the first reference layer is a second reference layer, each end of the second reference layer being located inward of an end of the first reference layer in the axial direction,
• the tread includes a tread main body and edge portions located axially outward of the tread main body,
• at least four circumferential grooves are formed on the tread main body,
• a wear resistance index of each edge portion obtained according to JIS K6264-2 is higher than that of the tread main body,
• an outer surface of the tire includes a tread surface, a pair of shoulder surfaces connected to the tread surface, and a pair of side surfaces connected to the shoulder surfaces,
• each shoulder surface includes an outer surface formed by the edge portion,
• a contour of each shoulder surface is represented by a circular arc having a center at an inner side,
• the tread main body covers the entirety of the belt,
• each end of the belt is located between the tread main body and the corresponding cushion layer, and
• a part of each edge portion is located between a corresponding sidewall of the pair of sidewalls and the corresponding cushion layer.