The invention relates to a truck or bus tire with a rubber tread of cap/base construction where the tread cap is composed of an emulsion polymerization prepared styrene/butadiene copolymer elastomer with a relatively random styrene content (E-SBR-A). Such E-SBR-A, in its uncured state, also has a relatively low Tg. In one aspect, the tire tread's tread cap may also be a blend of elastomers such as cis 1,4-polybutadiene and/or natural rubber together with said E-SBR-A and wherein the tread base elastomer is composed primarily of natural cis 1,4-polyisoprene rubber. In another aspect of the invention, said tread cap has a tread design composed of at least three circumferential continuous ribs designed to be road contacting, said ribs independently separated by continuous, circumferential grooves.