Study: Your Phone Can Tell If You’re Drunk


Your phone can give you turn-by-turn directions when you explore northern Colorado, play your favorite songs, movies, and games, alert you to appointments, track fitness program progress, take messages, and yes, your phone can even make calls.

According to recent research, smartphones could soon prevent drunk driving arrests.

Watching how you walk

A study published in the Journal of Alcohol and Drugs says phones can detect changes in the way you walk and determine if you’re too intoxicated to get behind the wheel.

Researchers recruited a group of 22 adult volunteers between the ages of 21 and 43. Each volunteer was weighed and then given weight-based doses of vodka cocktails calculated to achieve a blood-alcohol concentration (BAC) of .20 percent.

  • It should be noted that Colorado’s legal threshold is a BAC of .08 percent, though the state warns that “even if your BAC is less than .05 percent (the Driving While Ability Impaired limit), you can still be charged with a DUI if you show signs of impairment.”

Short, straight walks

After participants consumed their doses of vodka, phones were attached to their lower backs with elastic bands and they were then asked to perform a simple walking exercise that’s reminiscent of a field sobriety test. They were asked to walk 10 steps in a straight line, turn, and take 10 steps back.

They performed the walking test once an hour over a stretch of seven hours, as the phones’ accelerometers measured changes in forward and backward movements, as well as changes in movements up-and-down and side-to-side.

The phones’ accuracy

Researchers found that based solely on the phones’ analysis of changes in participants’ gait, they were able to determine when volunteers were intoxicated and when they were not 90 percent of the time.

“We found preliminary evidence supporting the use of gait-related features measured by smartphone accelerometer sensors to detect alcohol intoxication,” the researchers concluded.

More research planned

Dr. Brian Suffoletto, the study’s lead author, said he next plans to research if phones will also be accurate in determining impairment when held in the hand or carried in a pocket.

“We have powerful sensors we carry around with us wherever we go,” the Stanford University professor said, adding that we owe it to ourselves to take advantage of the powerful technology we carry with us every day.

Suffoletto said he hopes that within five years, phones will alert people “at the first sign of impairment” and stop them from drunk driving.