The drift velocity of electrons in a copper wire carrying steady current is of the order of

1. From v_d = -eEτ/m, drift velocity is proportional to field and relaxation time. 2. With typical current densities and free-electron density n ~ 10²⁸ m⁻³, |v_d| = I / (n e A). 3. For a copper wire this evaluates to about 10⁻⁴ m/s. 4. So drift velocity is remarkably small compared to thermal (~10⁶ m/s) or signal speeds. _Source: syllabus Physics, Ch 3 "Current Electricity", §3.5_