Holiday parties in Ohio are sometimes a little too much fun, but you stopped drinking a while ago and switched to coffee. You feel confident and competent to drive home, at least until you find yourself among all the other drivers inching through a sobriety checkpoint.

According to the Ohio State Highway Patrol, the U.S. Supreme Court settled the legality of sobriety checkpoints in 1990, upholding them as a tool for law enforcement officials as part of a deterrent program. You may have seen other parts of these types of programs, which can include articles and commercials. A critical requirement of law enforcement’s ability to use checkpoints is the site of the checkpoint itself. The location must have a long history of as the site of alcohol-involved crashes or DUIs. This ruling puts the burden on law enforcement to establish the need for a checkpoint.

Guidelines for checkpoints require the OSHP to notify the public about a week in advance of the checkpoint location, along with a general date and time of operation. The OSHP sends an advisory a few hours in advance with the exact location, day and time of the checkpoint. The advisory is typically picked up by members of the media and broadcast or posted online for you and other members of the public to read.

Law enforcement places reflective signs on the road approaching the checkpoint to inform you of the event and further, parks fully marked patrol cars at the signs as well. Traffic cones outline the path to the checkpoint, while emergency lights of several enforcement vehicles are left flashing to alert drivers. You can opt out of the checkpoint and simply turn around.

The court requires that the stopping of vehicles be performed in a uniformly random pattern, such as every third car. Officers can change the pattern to allow for better traffic flow when needed. If you are waved over, officers may only look for physical signs of alcohol impairment. If suspected of being drunk, you are taken to a secure area for a field sobriety test.

The National Highway Traffic Safety Administration developed the tests, which include having you walk and turn, stand on one leg or take a breath test, which can confirm impairment. Drivers who fail the tests are arrested on suspicion of DUI. This information about sobriety checkpoints is general in nature; it should not be considered legal advice.