(a) A municipality or a county may adopt an ordinance regulating the time, place, and manner of gatherings, picket lines, or protests by pedestrians that occur on State roadways and State highways.
(b) Nothing in this section shall permit a municipality or a county to impose restrictions or prohibitions on the activities of any of the following persons who are engaged in construction or maintenance, or in making traffic or engineering surveys:
(1) Licensees, employees, or contractors of the Department of Transportation.
(2) Licensees, employees, or contractors of a municipality.