(a) This chapter shall in no wise be construed to prevent the issuance by any public carrier of free passes or franks to its employees, officers, agents and their families, and the interchange between public carriers of passes or franks for their employees, officers, agents and their families, nor to prevent the carrying without fare upon electric trackless trolley coaches, street railways or buses of policemen, firemen, health officers and park guards in uniform, or plain clothes detectives, sheriffs, deputy sheriffs and other public employees wearing official badges.
(b) Nothing in this title shall be construed to prohibit the carriage or handling of persons or property free or at reduced rates by railroads for the United States, state or municipal governments, or to or from fairs and expositions for exhibitions thereof; or the free carriage of destitute and homeless persons transported by charitable societies and the necessary agents employed in such transportation; or the issuance of mileage, excursion or commutation passenger tickets; nor to prohibit any such corporation from giving reduced passenger rates to ministers of religion solely engaged in ministerial duties or to the United States, state or municipal governments; nor to prohibit any such corporation from giving free carriage to their own officers and employees; nor to prohibit the principal officers of any such corporation from exchanging passes or tickets with other railroad corporations for their officers and employees; nor to prohibit any such corporation from giving reduced rates of transportation to other railroad corporations for railroad construction, material, equipment or supplies.