Current in a wire: electric field velocity

Hi all,

I mysef wondered why the electric field velocity
is a fraction of c. I thik I understand why the drift
velocity is so low (some mm/s or lower) because
of electrons being scattered by the positive ions in
the metal lattice, but I cannot reconcile this mechanism
for explainig (to myself) the electric field propagation
between the two extremes of the wire.
Any enlightening is much appreciated.

Regards

Angelo
.