Every such board of chosen freeholders may make rules and regulations for the government and supervision of all such parks and recreation grounds and all boulevards, parkways and roadways located therein or leading thereto and may prescribe and enforce penalties not exceeding fifty dollars for the violation of any such rule or regulation and may prosecute all persons offending against the same, as disorderly persons. Such rules and regulations shall be plainly printed and conspicuously posted within such parks and public places as well as on the roads, highways and boulevards leading thereto.