The number of people arrested for driving while impaired in Minnesota is on the rise, and it's not just drunken drivers police are catching.

A majority of the 27,975 motorists cited for driving while impaired (DWI) last year had too much alcohol in their system, according to preliminary data released Thursday by the Minnesota Department of Public Safety. But a growing number of drivers arrested for being impaired by substances other than alcohol — namely cannabis, opioids and methamphetamine — contributed to a nearly 5% increase in DWI arrests last year when compared with 2018.

"The fact that we see those numbers going up does cause us some concern," said Mike Hanson, director of the Minnesota Department of Public Safety's Office of Traffic Safety. "There is no reason for us to arrest nearly 28,000 Minnesotans for DWI."

The number of annual arrests for driving under the influence peaked in 2006 at 42,000 and dropped for about decade before rising in the last couple of years.

Hanson attributed part of the recent uptick in DWI arrests to vigorous enforcement and changes in state law. Law enforcement also has become better at detecting and arresting impaired drivers, particularly drug-impaired drivers, he said.

The number of arrests of drug-impaired drivers from 2013 to 2017 was 78% higher than such arrests from 2008 to 2012, DPS data show.

Before 2018, police making a stop had to determine the specific substance impairing a driver before making an arrest. With a legislative change two years ago to include language about "all impairing substances" in the law, police now need only to determine on the scene that a driver is impaired in order to make an arrest. Police can call a drug recognition expert or another trained officer later to evaluate a driver and determine the specific substance, Hanson said.

Another change allows police to file for a search warrant electronically at the scene. That has reduced the time it takes to get a judge to sign off on requests to obtain blood or urine samples.

"That has made a huge difference," Hanson said. "We can have signed warrants by the time a person is taken to a medical facility or locked up to get a blood draw or have them submit to a urine test."

DPS has been more aggressive at trying to catch inebriated drivers, too.

It launched a program in 2015 to pay for 18 full-time peace officers whose sole job is to target and arrest impaired drivers. The officers were deployed on nights and weekends in the 10 counties with the highest number of drunken or impaired drivers, including Anoka, Blue Earth, Dakota, Hennepin, Olmsted, Ramsey and Washington counties.

This year, six additional officers will be deployed in sheriff's offices in Beltrami and St. Louis counties and police departments in Blaine, Crystal, Eden Prairie and St. Cloud.

"They have done yeoman's work by keeping communities safe by removing impaired drivers." Hanson said, noting that between Oct. 1, 2018, and Sept. 30, 2019, program officers have made 1,800 DWI arrests, or about 7% of such arrests statewide.

Nationwide, more than 1 million people were arrested for driving while impaired in 2018, according to a report released in December by the U.S. Drug Test Centers. The report drawing on data from the Centers for Disease Control and Prevention and the FBI found arrests for driving under the influence account for one in 10 arrests, meaning DWI arrests are more common than arrests for aggravated assault, burglary, auto theft or fraud.

"The bad news is that in several states, DUI arrests remain incredibly common," the report said.

Law enforcement in Minnesota made 187 DWI arrests between 6 p.m. New Year's Eve and 6 p.m. New Year's Day. Last year officers made 111 over the holiday.

This week, Utah enacted the nation's strictest drunken-driving law, allowing police to arrest drivers whose blood alcohol content is 0.05% or greater. In Minnesota, the legal limit to drive is 0.08%, the same as federal law, but Hanson said drivers can be arrested and charged with impairment below that level. Hanson didn't think Minnesota would follow Utah's lead in lowering the legal driving limit.

"Our job is to work with the laws that are in effect and then design programs we think will be effective in reducing and eliminating impaired driving," Hanson said. "We have made tremendous strides. We have tremendous work to do."