I would think that if an area had to be isolated in an attempt to halt the spread of a serious infectious disease that multiple available media resources would be employed to get the word out to the traveling public that the area is closed and that all traffic in or out halted for the sake of public health. Same for areas severely damaged by storms or similar events. I view a roadblock or checkpoints set up unannounced that halts the public’s right of free travel to be a bit more nefarious. Some call those a fishing expedition by LE. Regardless, they are looking for something. Most often its for proper vehicle registration, valid driving permits, and possible DUIs. During a wide-spread event of the like most discussed here it could be searching for contraband (whatever the powers define contraband to be at the time – guns, cash, supplies, etc.) and/or to categorize you as a “person of interest” in the course of questioning.
