A strategic checkpoint set up by the police in order to catch drunk drivers, while wasting everyone else's time. Pig blockages are easily noticed by the flashing lights and the faint smell of bacon, allowing drivers to plan an alternate route before it's too late to avoid. The smaller variation of the pig blockage is the piglet blockage.
Christian: There's a pig blockage on Main street!
Daniel: Thanks for telling me man, I had way too much booze and weed tonight.
Christian: No problem Daniel.
Daniel: Fucking pigs. (Proceeds to fall asleep and crash into a tree)