Current conduction by wires, and neurons in the absence of action potentials, is known as passive current flow. The rate of action potential limits the flow of information within the nervous system. This rate of action potential propagation along great distances is determined by the passive and active current flow.

One way to improve passive current flow is to increase the diameter of the axon to decrease the internal resistance to passive current flow.

Another way to improve the passive flow is to insulate the axonal membrane with myelin. This reduces the amount of current that would otherwise leak out of the axon and increases the distance that the current can flow passively.
Myelination, aka axon insulation, increases action potential conduction up to 150m/s compared to 0.5-10m/s conduction velocities of unmyelnated axons!

Speedy delivery of current (information) along axons is also due to the nodes of Ranvier. Nodes of Ranvier are gaps between insulated portions of the axon. The gaps create a place where the current can flow out of the axon so an action potential can be generated.

Action potentials are started at one end of the node, flow passively through the myelinated axon, and pop out the other side to jump to the next node. This jumping of action potentials is called saltatory.