Building a bridge takes a lot of planning before you actually start working on such a project. Building bridges must have many concepts to take into consideration. I believe that the most important concept to consider is Newton Third Law of Motion.

Newtons Third Law of Motion states that for every action there is an equal and opposite reaction. So for example, if one object A puts a force on another object B, then object B also puts an equal amount of force on object A. The third law is not taken lightly when building a bridge.