page_title: Random checkpoint
section_title: Legal guidelines
hierarchical_section_title: Random checkpoint / Sobriety checkpoints / United States of America / Legal guidelines
caption_attribution_description: English: A sobriety checkpoint in East Haven, CT. Also known as DWI Enforcement
context_page_description: A random checkpoint is a military and police tactic. In a military context, checkpoints involve the setup of a hasty roadblock by mobile truck- or armored vehicle-mounted infantry to disrupt unauthorized or unwanted movement or military activity and to check for valid identification and search for contraband, fugitives, or weapons that are not permitted in civilian hands. Random checkpoints are set up to achieve surprise, as opposed to known permanently located checkpoints, which suspects could circumvent. They are often established in locations where they cannot be observed by approaching traffic until it is too late to withdraw and escape without being observed.
  Patrol car-equipped police units regularly use random checkpoints to detect drivers who are suspected of impaired driving. Police also use hastily set up roadblocks to check cars and car trunks when they are pursuing an armed and dangerous fugitive. As with military checkpoints, sobriety checkpoints and fugitive roadblock searches are located in an area where drivers cannot see the checkpoint until it is too late to withdraw, and checkpoints are only set up on a temporary basis.
context_section_description: In approving "properly conducted" checkpoints, Chief Justice Rehnquist implicitly acknowledged that there must be guidelines in order to avoid having these checkpoints becoming overly intrusive.  In other words, checkpoints cannot simply be set up when, where and how police officers choose.  As often happens in Supreme Court decisions, however, the Chief Justice left it to the states to determine what those minimal safeguards must be, presumably to be reviewed by the courts on a case-by-case basis. To provide standards for use by the states, the National Highway Traffic Safety Administration subsequently issued a report that reviewed recommended checkpoint procedures in keeping with federal and state legal decisions.
  An additional source of guidelines can be found in an earlier decision by the California Supreme Court, Ingersoll v. Palmer (1987) 43 Cal.3d 1321, wherein the California State Supreme Court set forth what it felt to be necessary standards in planning and administering a sobriety checkpoint.
  The Ingersoll guidelines fall under the following general headings:
  Decision making at the supervisory level
  Limits on discretion of field officers
  Maintenance of safety conditions
  Reasonable location
  Time and duration
  Indicia of official nature of roadblock
  Length and nature of detention
  Advance publicity
  The U.S. Supreme Court's decision of Michigan Dep’t of State Police v. Sitz (1990) 496 U.S. 444, was decided after Ingersoll. The U.S. Supreme Court did not criticize any of the Ingersoll guidelines, nor did it recommend any others; seemingly making it the law of the land and leaving the decision of whether to permit sobriety checkpoints to the individual states. In People v. Banks (1993) 6 Cal.4th 926, which was decided after Ingersoll and Sitz, and incorporated a discussion of both cases in the opinion, the California State Supreme Court held that advance publicity is not an essential element of the constitutionally of a valid drunk driving roadblock. The Court concluded that although advance publicity remains a factor to consider, the lack of it alone does not render the roadblock unconstitutional. People v. Banks (1993) 6 Cal.4th 926.
  The following considerations expand upon the general headings listed above:
  Decision making must be at a supervisory level, rather than by officers in the field.
  A neutral formula must be used to select vehicles to be stopped, such as every vehicle or every third vehicle, rather than leaving it up to the officer in the field.
  Primary consideration must be given to public and officer safety.
  The site should be selected by policy-making officials, based upon areas having a high incidence of drunk driving.
  Limitations on when the checkpoint is to be conducted and for how long, bearing in mind both effectiveness and intrusiveness.
  Warning lights and signs should be clearly visible.
  Length of detention of motorists should be minimized.
  Advance publicity is necessary to reduce the intrusiveness of the checkpoint and increase its deterrent effect.
caption: A checkpoint in the United States.
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