At DUI checkpoints, law enforcement officials evaluate drivers for signs of alcohol or drug impairment at certain points on the roadway. Vehicles are stopped in a specific sequence, such as every vehicle, every other vehicle or every fourth, fifth or sixth vehicle. It usually depends on the amount of traffic at a given location. Drivers will usually be asked for proof of drivers license and insurance plus the use of seatbelts if so required in that state.

Also, a quick look at the safety condition of your vehicle such as lights, tires, and a check for a currtent tag may be made. Officers are allowed by law, to look into your vehicle (passenger compartment only) from the outside even at night using flashlights.

Saturation patrols are concentrated enforcement efforts that target impaired drivers by observing moving violations such as reckless driving, speeding, aggressive driving, and others. Saturation patrols are spread over a larger geographic area. In saturation patrols, motorists and motorcyclists are evaluated on an individual basis because certain behaviors have been displayed to law enforcement officers while the vehicle is in motion.

DUI checkpoints and saturation patrols educate the general driving public that breaking traffic laws is a serious problem and that violators will be punished.

In 1990, the U.S. Supreme Court upheld the constitutionality of sobriety checkpoints in Michigan v. Sitz. The court decided that the interest in reducing the incidence of impaired driving was sufficient to justify the brief intrusion of a properly conducted sobriety checkpoint. If conducted properly, sobriety checkpoints do not constitute illegal search and seizure in most states.

Thirty-nine states, plus the District of Columbia, can legally conduct sobriety checkpoints. The use of sobriety checkpoints as a deterrent is restricted or prohibited in the following states: Alaska, Idaho, Louisiana, Michigan, Minnesota, Oregon, Rhode Island, Texas, Wisconsin, Washington and Wyoming. Please check the laws in your area to find out if sobriety checkpoints are legal in your state.

Surveys indicate that 75 percent of Americans favor the use of sobriety checkpoints as a law enforcement tool. The International Association of Chiefs of Police, Operation C.A.R.E. and the National Sheriffs Association favor them. Citizen groups such as Mothers Against Drunk Driving, Remove Intoxicated Drivers, Safe Communities, Students Against Destructive Decisions and Citizens Against Drug Impaired Drivers (C.A.N.D.I.D.) strongly favor their use. Private entities such as the Nationwide Insurance and the National Commission Against Drunk Driving have advocated their increased use for many years. Federal agencies such as the National Transportation Safety Board and NHTSA also strongly favor their use.

Sobriety checkpoints and saturation patrols are generally conducted on weekend nights at locations where impaired driving is high according to arrest and crash records. However, sobriety checkpoints and saturation patrols can take place anywhere or at any time in a community.

According to the National Highway Traffic Safety Administration (NHTSA), an impaired driver can be on the road 772 times before getting caught and being arrested. Seasonal increases in alcohol and drug use help local agencies target their enforcement efforts. Sobriety checkpoints and saturation patrols provide law enforcement officials with effective tools for removing impaired drivers from roads and highways.

Sobriety checkpoints and saturation patrols help law enforcement officials detect and arrest impaired drivers. They also are a strong deterrent to people who might choose to drive after drinking or using drugs by increasing the perceived risk of arrest.

Some think that sobriety checkpoints cause traffic jams and detain people for long periods of time. Well-conducted, well-planned checkpoints delay drivers no more than a few minutes, or the length of an average traffic signal.

Some think that checkpoints are costly, time-consuming and labor intensive; however, small-scale checkpoints can be conducted with as few as two to five officers.