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Ask The DUI Expert: How Do Police Recognize Drunk Drivers on the Road?

This week, we ask Officer William Pelarenos: What is it that makes a police officer consider pulling over a car? What are the tell-tale signs of a drunk driver?

Officer Pelarenos: Police Officers always look for traffic violations such as speeding, improper lane usage or driving without the headlights on. These are the most common violations, but then of course you will have Police Officers stopping vehicles for expired license plates or missing a taillight. For several years, one town was stopping cars for missing the light over the rear license plate. How many people check the light over their rear license plate before driving at night? Few to none. This violation resulted in many DUI arrests for this town but it also created a problem in court when defense attorneys would argue the case stating that there was no bad driving or erratic driving on the part of their client. If the defense attorney can knock out the probable cause ticket then the case is dismissed on, ‘finding of no probable cause.’

There are other circumstances for drivers to be pulled over, such as DUI checkpoints, also known as Roadside Safety Checks. In this case, a roadway is reduced to one lane, the police pick out cars in a selected pattern to check. The pattern can be anything as long as it’s strictly followed. It could be every third car, every seventh car, every tenth car, etc. During my years with the Police Dept., the roadside checks always resulted in at least one DUI arrest, usually it was two. Sometimes it got crazy and we had four or five DUI arrests.

Then there are the citizen complaints--people who call on their cell phones and report erratic driving. The most common complaint is when cars are drifting across lanes. This is a tell-tale sign of drunk driving. The proliferation of cell phones over the past two decades has made this a common occurrence. Then of course, there is phenomenon of drunk drivers sleeping in their cars. Sometimes they are pulled off on the shoulder of the road but many times they are not. I can think of at least ten times during my career, that I found drivers asleep at the wheel with the car in drive and their foot on the brake. The last case I had like this was back in June of 2012. It was 5:30 AM on a Sunday morning when I saw a car stopped at a green light while other vehicles were driving around him. I walked up to the car and I saw the driver sleeping with the car in drive and his foot on the brake. Unbelievable as it sounds, this man was asleep but his foot was still applying pressure to the brake. I reached into the car, I shifted the transmission from drive to park and then I woke him up. True story. Needless to say, he was arrested for drunk driving.

Got a DUI question for Officer Pelarenos? Ask him at, or find him on Twitter, @policeproject1.

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