How do you know the person was "drunk"? Many times if you're in an accident(there are many CAUSED by redlight cameras BTW), they will say it's "alochol-related" or charge you with DUI even if your BAC is something like .01-.06. They can say because you got in an accident and were disoriented or confused(which many people after bad accidents are) that's proof that you were impaired.
The fact is only 2,932 innocent people were killed because of drunk drivers in 2002....and the numbers have only gone down. In 2009 there were 10,839 total deaths versus 13,472 in 2002, so obviously the innocent victims of drunk driving would be even less now.
Not to mention the increase of the number of cars on the road means we have more cars, more people driving, more people driving after drinking(but not drunk), and likely more people driving over the limit also....yet we're at the lowest chance of being effected by a drunk driver ever and the death numbers have gone down. On the other hand, the % has stayed the same for decades because you can't stop drunk driving with laws, it's predominantly an emotional problem/disease. Non-alcohol fatalities have been right at 62% and alcohol fatalities have stayed at 32% for 10+ years.
Still think MADD does ANYTHING besides pay themselves higher salaries and try to get us closer to prohibition? If you do, you don't believe in your own government statistics that MADD used to convince you deaths have gone down because of their efforts in the 1st place. (Sure they've gone down, but so have the total fatalities...percentage-wise though, nope.)
The ones that "require" notifying the public have done so to make sure they'll be on proper legal grounds for anyone that decides to challenge it. (aka:Covering their asses)
Since these checkpoints all survive only because they're considered a "reasonable" seizure under the 4th amendment since the public safety need outweighs the "minor intrusion" on the public. Checkpoints that are set up without road signs warning motorists in advance and/or are set up on a road which provides the motorist no means to do a U-turn or otherwise avoid it run the risk of being declared "unreasonable" when challenged in court.
That's mainly because the courts have noted that with proper warnings, the public won't be surprised by it and won't be in a situation where they feel they're being singled out. That's also the reason the checkpoints are usually set up on busy roads and not some side road off the beaten path where the encounter would be more intimidating and unexpected.
There are a few somewhat smaller factors that can be used to find the way they do it reasonable or unreasonable, but those are the main points at issue here at least.
...And here's some facts that the majority "should" have known back then when they decided the public safety concern outweighed the "limited intrusion" of our privacy, as shown by the breakdown by one of the dissenting justices:
"in 1988 there were 18,501 traffic fatalities involving legally intoxicated persons. If one subtracts from this number the 10,210 legally intoxicated drivers who were themselves killed in these crashes, there remain 8,291 fatalities in which somebody other than the intoxicated driver was killed in an accident involving legally intoxicated persons (this number still includes, however, accidents in which legally intoxicated pedestrians stepped in front of sober drivers and were killed). Fatal Accident Reporting System 1988 Overview, p. 1; see also n. 15, supra.
By contrast, in 1986 there were a total of 19,257 murders and non negligent manslaughters. Of these, approximately 11,360 were committed with a firearm, and another 3,850 were committed with some sort of knife. U. S. Dept. of Justice, 1987 Source book of Criminal Justice Statistics 337 (1988).
From these statistics, it would seem to follow that someone who does not herself drive when legally intoxicated is more likely to be killed by an armed assailant than by an intoxicated driver. The threat to life from concealed weapons thus appears comparable to the threat from drunken driving.
Nowadays with the safety advances, awareness, and greater amount of cars on the road, you're even more likely to die from these causes first:
28.77 times more likely to be killed by a sober driver
13.52 times more likely to die from a fall
8.52 times more likely to be poisoned
4.57 times more likely to die from an injury at work
3.66 times more likely to drown
2.92 times more likely to choke to death
2.34 times more likely to die while under a doctor’s care