What is the maximum possible speed at which current can travel?

The maximum possible speed at which current can travel is associated with the speed of light. This speed, approximately 299,792 kilometers per second (186,282 miles per second), represents the fastest rate at which electromagnetic signals, which include electrical signals, can move through a vacuum. When electricity travels through a conductor, such as a wire, it is the electromagnetic waves generated by the movement of charges that propagate at this speed.

Although the actual drift velocity of electrons in a conductor is much slower, the influence of their movement (the electrical signal) is transmitted at or near the speed of light in insulated conductors. In this context, the correct understanding is that it is the signal associated with the current that travels at the speed of light, rather than the movement of individual charge carriers, which is much slower. This principle is fundamental in electrical engineering and physics, especially in communications and power systems, where signals must be transmitted rapidly over distances.