The Colorado Department of Transportation has channeled its inner Amazon Prime Day to offer breathalyzers for half-off in hopes of curbing drunk driving.

It turns out having a machine to tell drinkers how drunk they are before they get behind the wheel of a deadly machine makes sense.

“You should be the last person to determine whether you have had too much to drink,” said CDOT spokesman Sam Cole. “People guess in the wrong direction. They’re in denial and they don’t want to deal with the fact that they shouldn’t drive.”

CDOT partnered with BacTrack to sell the devices to Colorado residents for between $30 and $50 depending on the model. Last year the same program resulted in 3,000 sales, launching Colorado to the top in terms of per capita breathalyzer owners, Cole said.

The promotion complements that time of the year leading up to Labor Day when law enforcement agencies put extra resources into stopping drunk drivers from risking their lives and the lives of others.