Electric current is a rate of flow of charge which is mathematically devised as current I=dq/dt where dq is the amount of charge flows in a short time dt. Charge is nothing but the presence or absence of electrons. Electrons as a whole do not constitute any direction. Again, charge is also not flowing towards a particular direction as like the heat energy doesn't flow towards a scrupulous direction or you may say the current of water through streams is also not following any exacting direction.

The heat energy only flows if there's any difference of temperature between source and destination. Same way, the water current is also flowing only when there’s a difference between the height of the source and the sink. The same is to be told for electric current. Whence there’s a disparity between voltages (amount of electric charge) of two points, then only electric current (stream of electric charges) flows from high voltage towards low voltage without following a pre-decided straight-line path. Whatever is the path, charges or, to be precise, electrons flow from higher collection of charges to a lower one. It's customary to assume that charges or electrons flow from lower voltage to higher voltage and, reversely as current is thought of the flow of positive charges (absence of electrons), it's flowing from the higher to the lower one without following a straight-line. Thus, no question should come about the vector addition for a scalar quantity like electric current.