Sec. 4. The Indiana department of transportation and local authorities in their respective jurisdictions may in their discretion issue special permits authorizing the operation upon a highway of:
(1) traction engines;
(2) tractors having movable tracks with transverse corrugations upon the periphery of movable tracks; or
(3) farm tractors or implements of agriculture designed to be operated primarily in a farm field or on farm premises;
the operation of which upon a highway would otherwise be prohibited under this chapter.