It is unlawful for any railroad to charge or receive any greater compensation for carrying, receiving, storing, forwarding, or handling articles of the same character and description for a shorter than a longer distance in one continuous carriage; provided, that:
(1) Nothing in the General Railroad Law contained shall be construed so as to require any corporation or combination of corporations to regulate their charges for shorter distances by their proportion of through rates between terminal or junctional competitive points.
(2) If one corporation uses, operates, or otherwise controls, wholly or in part, several lines or divisions of theretofore independent railroads within the State, the Public Service Commission may fix different rates of toll or compensation for freight traffic on each of such previously independent lines or divisions.
(3) The commission may make special rates for the purpose of developing all manufacturing, mining, milling, and internal improvements in this State.