There were several steps taken by him to implement Pax Romana which included "Res gestae" like bringing civil war to a halt, moreover he provided Plebeians with more say in the authority, he also made sure that those who were in opposition or enemies are contained. And finally he created big building projects which resulted in employment.
All of his arrangements and steps resulted in long term effects like there were no battles and various people from different backgrounds got along. His also allowed the trade and commerce to boom in the era, building projects like Maximus and adueducts. New philosophies were formed then.