Lakeville police on Thursday arrested a semitrailer truck driver on suspicion of driving with more than five times the legal blood-alcohol limit for commercial operators.

The 49-year-old man from Pelican Rapids, Minn., was in the Dakota County jail on Thursday evening, pending charges.

He has two previous drunken-driving convictions, in 1998 and 2010. The Star Tribune generally does not print the names of suspects before they are charged.

Under state law, commercial-vehicle operators are considered intoxicated if they have blood-alcohol concentrations of 0.04 or greater, compared with 0.08 for noncommercial drivers.

A preliminary breath test at the scene registered the trucker's blood-alcohol concentration at 0.21, said Lakeville Police Chief Tom Vonhof.

"Any time someone's under the influence and operating a large vehicle or a heavy vehicle, like a semitractor trailer, it's a public safety concern," he said.

"And we're glad that we were able to stop him and get him off the road before something happened."

Vonhof said police had been called to Cedar Avenue and County Road 70 about 8:30 a.m. on a report of a possible drunken driver. The trucker had just finished unloading in the area and was driving without his seat belt on.

The trucker's most recent drunken-driving conviction was in Otter Tail County, and he's still on probation for that, court records show.

Neither conviction involved a commercial vehicle.

But questions remain about why someone with a 2010 drunken-driving conviction was driving commercially. Typically, truckers must have a record clean of drunken driving infractions for at least three years to be insured.

Such an arrest was unusual within the city limits.

"I haven't seen a commercial vehicle DUI arrest like this in some time; we do not come across it very often," Vonhof said.

Joy Powell • 952-882-9017