A recent study published in Alcoholism: Clinical and Experimental Research describes a connection between highly visible police traffic stops and the level of blood alcohol in a driver's system. DUI traffic stops in San Diego can occur in several ways. The study looks at DUI Checkpoints as one example of a highly visible traffic stop method.
Most drivers in San Diego have seen or gone through a DUI checkpoint. These are specific sections of a busy street that are marked off and created to funnel traffic through a series of controls. Once a car enters the checkpoint lane multiple officers are able to observe drivers from a distance and also speak with a driver. Although a driver may speak to only one police officer, there are in fact 20-30 officers in the immediate area who are there to find and arrest drunk drivers.
San Diego DUI Attorney George Gedulin on the study, “The study seems to answer its own hypothesis at the outset, it looks to favorable data set that supports the premise of the study.”
The study finds a strong connection in counties where drivers are more often contacted or stopped by police looking for DUI drivers, and the BAC level in those drivers. Basically, someone who lives in a county with a high rate of DUI checkpoints is less likely to be driving with a blood-alcohol level over the legal limit. The idea is a simple one and seems to support police departments increasing use of checkpoints; more DUI checkpoints equals less drunk drivers on the road. The study however does not address some major errors in its own methods and ignores other important factors relating to drinking and driving.
A finding that higher rates of DUI related stops cause drivers to drink less before they drive assumes that the enforcement is causing reduced drinking. The drinking data is completely dependent on people taking blood alcohol tests. The strong data for these tests exist where there are more people to take blood alcohol tests, more data requires more stops. So while the study may have good data from counties where DUI checkpoints are common and widely used, areas, where there are fewer DUI stops, has far weaker data.
There is also an entire blackout in the study in addressing those drivers who drink well beyond excess, and whose BAC may be .20 or higher. Alcoholic drinkers or binge drinkers are by definition giving little consideration to how prevalent DUI enforcement is. The consideration of being caught or consequences of drunk driving does not enter into their normal thinking. Drivers who drink to excess and plan to drive give little to no thought of DUI enforcement, and are more likely to know how to avoid pre-determined DUI checkpoint locations.
What DUI checkpoints do in fact is violating the constitutional rights of all drivers who are subject to random search and seizure with no probable cause. Drivers subject to such invasive search and questioning in the name of driving safety. The most dangerous drunk drivers on the road are those with significantly increased blood alcohol levels, .20 or higher. To subject, the average driver who may have had nothing to drink or only a couple beers to such invasive search is violating and not the best method to prevent drunk driving.