Some officers check every other vehicle to speed things up. Typically these roadblocks are set up during the late night, early morning, or during the weekends. These are the hours during which most people are likely to drink and be on the road.
Once you are stopped the officers will ask you to roll down your window to speak with you. They will ask you for your driver's license, registration, and proof of car insurance. They will also ask where you are coming from or where are you heading now.
If the police officers suspects that you have been drinking, they may ask you whether you have been drinking tonight. The officers will also begin to look for signs of intoxication. These signs include:
If you display any of these symptoms, the police officers may give you a quick breathalyzer test. If the police doesn�t have a breathalyzer with them, they will ask you to move your vehicle to the side and step out of the vehicle to give a roadside DUI test.
If you fail the DUI test then you will be arrested for a DUI you will be taken to the precinct to take a take a chemical test (blood, breath, or urine) to give a more accurate reading of your blood alcohol concentration.
Going through these checkpoints can be an inconvenience for most drivers. If you want to avoid them beforehand, you can find out the location where the checkpoint is being held. The best place I have found is at http://www.roadblock.org/registry.htm .
Some Internet services send you an alert via text message or email of all the different checkpoints in your area. These however do charge you a price to use their service.
If you're not able to find a checkpoint before hand you can still avoid them. If you are stuck in a DUI checkpoint line, you can avoid it by doing a legal maneuver ( such as a legal U-Turn) and drive away.
Not all states enforce the checkpoints. This is because some states have argued that it's unconstitutional to conduct these tests on every driver. Therefore it is illegal to enforce them. The following 38 states enforce the checkpoints:
* Alabama * Arizona * Arkansas * California * Colorado * Connecticut * Delaware * D.C * Florida * Georgia * Hawaii * Illinois * Indiana * Kansas * Kentucky * Louisiana * Maine * Maryland * Massachusetts * Mississippi * Missouri * Nebraska * Nevada * New Hampshire * New Jersey * New Mexico * New York * North Carolina * North Dakota * Ohio * Oklahoma * Pennsylvania * South Carolina * South Dakota * Tennessee * Utah * Vermont * Virginia