North Carolina is a checkpoint state – the constitution allows police to set up a checkpoint to stop drivers and ask if they’ve been drinking. It’s not hard to figure out where they are – websites and social media feeds broadcast their location so drivers never need to be surprised by them.

In some states the police must broadcast the location of the checkpoint in advance, but North Carolina only requires that blue lights are flashing. And if you turn around to avoid the checkpoint, the police can stop you and ask you why.

Tweeting DWI Checkpoint Locations: Enabling DWIs?

Some, police spokespeople, including the Iredell County Firewire Facebook feed, claim that posting roadblock info is merely helping drunk drivers avoid detection. And it’s true that an impaired driver could check a warning site and take a different route.

But the First Amendment allows citizens to inform others of police activities, and there’s nothing secret about the checkpoints.

How Sobriety Checkpoints Help No Matter What

Even if the warning sites help a few drivers evade the breathalyzer, the checkpoints still catch a fair number. And more important, the presence of the roadblocks has a salutary effect on people heading out for a social gathering – it reminds them that police are out in force, and that they had better stay sober if they’re driving home.

Not all states use checkpoints, and the constitutional disagreements about stopping vehicles randomly will no doubt continue. But states in which they are permitted do benefit from them – even when people don’t get near them.