A blood alcohol content (BAC) of 0.08 is the legal limit for driving, but more than 29,000 Minnesotans got DWIs in 2011, many of whom didn’t know they’d had too much. Enter IntoxBox Interactive Breathalyzers.

IntoxBox sits on the wall and has a 19-inch touchscreen. For a dollar or two, users get a chance to guess their BAC before blowing through a disposable straw into the machine. The machine reveals the person’s BAC, and if the individual decides not to drive, IntoxBox can call them a taxi.

“We want to raise awareness at the point of the incident,” says Ryan Walden, president of IntoxBox-creator Walden Innovative Resources, “to benefit people who are unsure or unwilling to risk it.”

Walden got the idea for the device back in 2009, while attending Cornell College in Iowa. One of his friends got arrested for DWI on his way home from a football game, with no idea he was over the limit.

Once Walden graduated, his father and brother got involved, taking executive roles in the St. Paul–based company. After years of development, IntoxBox went on the market last December and is now in 25 bars throughout the Twin Cities, and sold through 18 different franchisees around the country.

One of those is Toby Keith’s I Love This Bar and Grill in St. Louis Park, which has two IntoxBox machines. According to General Manager Jason Sisk, about 30 to 40 people test their BAC per night.

IntoxBox’s entire operation has been financed by the Walden family and has earned just less than $400,000 in gross sales so far. There is no cost to the bars that house the machines, and they typically receive 25 percent of the revenue.

“We just want to put a stop to drunk driving caused by lack of information,” Walden says.