In Chief Justice Rehnquist's response, he stated: "In summary, the balance of state interests in preventing drunk driving drunk driving, the extent to which this system can reasonably be considered to further that interest, and the degree of intrusion on individual motorists who are briefly stopped weighs in favor of the state program. We therefore believe that it is consistent with the Fourth Amendment. (Justia Law) I believe the level of "trespassing" is downplayed in her answer, because if you have ever gone through a drunk driving checkpoint (I haven't, I don't (I've only seen instructional videos and reaction videos), they seem to have several of the police around your vehicle looking out your windows looking for a single thing that would be out of place to give them the two most important things never uttered: "probably