The Supreme Court has ruled these roadblocks are unconstitutional in
Indianapolis v. Edmond
quoted from a wikipedia article
I am happy that the Supreme Court did what I feel is the right thing overall but I am very disturbed that some of the conservatives on the bench dissented. Like I try to remind people, both liberals and conservatives can be equal opportunity freedom killers. Where one group threatens some of our freedoms or what should be our freedoms, the other picks up the slack that the first group is neglecting to attack. That's why I trust Libertarians more so than either the Republicans or Democrats. They seem to be the party that is most liberty orientated at the individual and family levels.
Here's an article about an Illinois Sheriff who still uses the drug checkpoints despite knowing they are unconstitutional.
http://effinghamdailynews.com/local/x75194005/Drug-checkpoint-questionable
I guess they figure some people, especailly poor people, won't try to fight the charges and will cop plea deals. What needs to happen is for them to be sued over it I guess.