200.3

[lakee911]

...but what about....

Exception No. 2: Under engineering supervision,
grounded neutral conductors in sizes 2 AWG and larger
shall be permitted to be run in parallel for existing
installations.

What does this mean? An engineer has to watch them 'run' it in 'parallel' to the 'existing'? Do train conductors count? That's train drivers, not train wires.