Fibers are used instead of metal wires because signals travel along them with less loss and are also immune to electromagnetic interference.

Because these signals travel close to the surface and lower frequencies produce lower resolutions, low-frequency systems are generally used for tracking ships, rather than aircraft.

The distance can be directly calculated from the time of arrival as signals travel with a known velocity.

These signals travel along the optic nerve fibers to the brain, where they are interpreted as vision in the visual cortex.

The level of neurofilament gene expression seems to directly control axonal diameter, which in turn controls how fast electrical signals travel down the axon.