This study presents a new mobile robot with passively articulated driving tracks for high terrainability (TA) and maneuverability (MA) on unstructured, rough terrain. The mobile robot consists of four driving tracks, two rocker links, and four pitch-roll two-degrees-offreedom (2-DOF) passive joints. For performance evaluation, the proposed mechanism was compared with several existing mechanisms, including four tracked mechanisms and three wheel linkage-type mechanisms. Dynamic simulations of reference posture tracking control on three different types of rough terrain using DAFUL confirmed that the incorporation of 2-DOF passive joints and a rocker DOF can contribute to the reduction of TA and MA. TA and MA are reduced by approximately 25.48 % and 44.51 %, respectively, compared with the seven existing locomotion mechanisms. The reasons for improved TA and MA are discussed in terms of three structural features of the proposed mechanism. Finally, the optimization design of the mechanism is constructed.