A Youtube video (4th of July DUI Checkpoint) posted by a Tennessee man has some questioning what their rights are when pulled over at a DUI checkpoint.
A DUI checkpoint is a location where police officers set up stations to check drivers for signs of driving impairment from intoxicants. Some states allow these checkpoints, where others do not. In Washington, they are not currently permitted.
If you are traveling to other states and curious about the use of checkpoints in those states please see the chart available from the Governors Highway Safety Association. (http://www.ghsa.org/html/stateinfo/laws/checkpoint_laws.html)