A present invention relates to a composite road module, unit and system. The composite road module comprising a first road and a second road extending substantially in parallel, one of the first road and the second road being configured for vehicles to travel according to a left-hand traffic rule, the other being configured for vehicles to travel according to a right-hand traffic rule, the first road comprising a first lane and a second lane, the second road comprising a third lane and a fourth lane, wherein the first lane and the third lane are in communication with each other, and are provided for vehicles to travel in a first direction, and wherein the second lane and the fourth lane are in communication with each other, and are provided for vehicles to travel in a second direction opposite to the first direction.