“When police officers use hand-held passive alcohol sensors at sobriety checkpoints, they identify significantly more drivers with elevated BAC levels than they do without the sensors. For example, one study found that by using standard sobriety checkpoint protocols, police officers were able to identify 55 percent of drivers with BACs of 0.10 or higher and 26 percent of drivers with BACs between 0.05 and 0.10. By incorporating passive alcohol sensors, the officers’ detection rates increased to 71 and 39 percent, respectively (Ferguson, Wells, and Lund 1995, 23–30). Another study found that the DWI arrest rate for officers using passive sensors at sobriety checkpoints was more than double that of officers at checkpoints that did not employ passive sensors (Voas, Rhodenizer, and Lynn 1985).”

“The NTSB concludes that passive alcohol sensors are an effective yet under-utilized technology for making an initial determination of the presence of alcohol during traffic stops or at sobriety checkpoints. Therefore, the NTSB recommends that the 50 states, the Commonwealth of Puerto Rico, and the District of Columbia include in their impaired driving prevention plan or highway safety plan provisions for conducting HVE [High Visibilty Enforcement] of impaired driving laws using passive alcohol-sensing technology during law enforcement contacts, such as routine traffic stops, saturation patrols, sobriety checkpoints, and accident scene responses.”

“The increased use of passive alcohol sensors during HVE will not only increase the likelihood that drivers using alcohol will be detected by law enforcement; it may also act as a deterrent by increasing the perception that drivers risk arrest and swift and certain consequences if they choose to drive after drinking.”

Except from May 14, 2013 National Traffic and Highway Safety Report “Reaching Zero:Actions to Eliminate Alcohol Impaired Driving” Safety Report NTSB/SR-13/01 PB2013-106566