As someone who mentions "civil rights guaranteed by the U.S. Constitution" in your signature, it's both ironic and hypocritical of you to be against preserving the 4th amendment and in favor of denying people "civil rights guaranteed by the U.S. Constitution" in the form of checkpoints. Seeing as how checkpoints take the 4th amendment and run it through a paper shredder.
I should also ask if you or anyone else that is in favor of killing our 4th amendment rights has ever actually used Trapster? It's good for finding out about accidents, dangerous turns, school zones, bad intersections, red light cameras (which typically have shorter yellow lights and more rear end accidents), and countless other road hazards. Being able to preserve my 4th amendment right by alerting me to a checkpoint that I can then avoid is just a plus. As I said before, I've never drank or done drugs. I care about the fact that checkpoints kill one of our fundamental rights.
I'm not really taking a side on your argument but I think it is interesting to note that you could probably apply the concept of "open fields" to searches/DUI checkpoints. It would counter the random search ruling(s) but I'm sure a good case could be made legally either way.
Open fields
Main article: Open fields doctrine
Similarly, "open fields" such as pastures, open water, and woods may be searched without a warrant, on the ground that conduct occurring therein would have no reasonable expectation of privacy.
The doctrine was first articulated by the Supreme Court in Hester v. United States, 265 U.S. 57 (1924), which stated that “the special protection accorded by the Fourth Amendment to the people in their ‘persons, houses, papers, and effects,’ is not extended to the open fields." The decision was rendered on the ground that "open fields are not a 'constitutionally protected area' because they cannot be construed as "persons, houses, papers, [or] effects.
In Oliver v. United States, 466 U.S. 170 (1984), the police ignored a "no trespassing" sign and a fence, trespassed onto the suspect's land without a warrant, followed a path for hundreds of feet, and discovered a field of marijuana. The Supreme Court ruled that no search had taken place, because there was no privacy expectation regarding an open field:
open fields do not provide the setting for those intimate activities that the Amendment is intended to shelter from government interference or surveillance. There is no societal interest in protecting the privacy of those activities, such as the cultivation of crops, that occur in open fields.[58]
Source: http://en.wikipedia.org/wiki/4th_Ammendment