Sobriety Checkpoints

Sobriety checkpoints are roadblocks on public roads at which officers systematically stop vehicles in order to investigate drivers’ sobriety. All drivers who are stopped are required to submit to a sobriety test, usually in the form of a portable breathalyzer test or field sobriety test, in order to determine possible alcohol impairment.

Sobriety checkpoints, set up at times during the day when drunk driving typically occurs, seek to deter DUIs. The Centers for Disease Control have found that in states where sobriety checkpoints are used, alcohol-related crashes have been reduced by about 20%.

Due to the invasive nature of sobriety checkpoints, many question the validity of the practice. Although courts in the majority of states have ruled that sobriety checkpoints are upheld by federal and/or state constitutions, several states consider checkpoints illegal under varying interpretations.

States that do not allow sobriety checkpoints include:

  • Alaska
  • Idaho
  • Iowa
  • Michigan
  • Minnesota
  • Oregon
  • Rhode Island
  • Texas
  • Washington
  • Wisconsin
  • Wyoming


The debate over the constitutionality of sobriety checkpoints centers around the concept of being searched, questioned, and subjected to testing without due reasonable suspicion or probable cause–a potential violation of the Fourth Amendment. Due to this controversy, many states have amended or added specific exceptions to their normal civil protections in order to allow sobriety checkpoints in their state. Guidelines are set up in order to avoid over-intrusiveness.

Generally, sobriety checkpoints are set up on a public road at a time and location chosen due to its past record of high DUI incidence. A neutral formula is used in to order to select the vehicles to be stopped. For example, an officer may pull over every sixth car that goes by.

Officers require drivers to submit to a breath analysis test. Usually conducted with a portable breathalyzer, the test measures blood alcohol concentration by analyzing the driver’s breath. The testing procedure at sobriety checkpoints is determined on a state-by-state basis. Some routines may also include having the driver step out of the car to perform a series of field sobriety tests.

Special caution is taken at sobriety checkpoints in order to ensure that the length of detention is not too long and cumbersome of a delay. There are also limits to the length of time the checkpoints are allowed to be active on any given public road.

There’s no doubt that systematically stopping cars and conducting sobriety tests is a surefire way to prevent driving under the influence, as it is a very direct approach. However, despite efforts to make sobriety checkpoints as minimally intrusive to the driver as possible, it’s easy to see why the debate over constitutionality continues.