No they aren't. If they were, then you would see checkpoints set up all over town on a daily basis in order to protect your loved ones. The fact that you don't proves that in fact, that is not the motivation. The real motivation is to A) Make it look like they are making a token effort and B) income generation when there are budget shortfalls to be made up. Nothing more. Again, if this was really about protecting people from drunks and if that really worked, you would see these used daily in your town.
Someone else had it right....if you really want to stop drunk driving, put police in the parking lots of bars. That will make people think twice. A DUI checkpoint, will not. Nor will it catch all the drunks leaving all the bars. There ARE plenty of other roads after all. Checkpoints are too limited in scope to be very effective at dealing with the real problem.
TOTALLY agree. DUI checkpoints serve one purpose, and one purpose only. To make police departments money and keep cops away from criminals they should be fighting. You only see them during major events/times of the year or in wealthier areas where they know people being stopped can pay up. They have a ****ing quota and in stead of doing their jobs they just try to do it all at once, the same reason at the end of the month they pull people over non stop for speeding tickets, rather than at a constant rate.