The annual number of traffic crashes involving drugs has reached a decade-high in Michigan, according to police statistics.

Crashes involving drugs went from 1,581 in 2006 to 2,215 in 2015, a 40 percent increase, Michigan State Police data cataloging UD-10 crash reports shows.

Police say the increase is because of better-trained officers but also because drugged driving is on the rise in Michigan.

Here are seven takeaways related to the decade of data and Michigan drugged driving:

1. Crashes involving drugs caused 1,603 deaths and 12,544 injuries. There were 18,493 crashes involving drugs from 2006 to 2015, according to traffic crash reports provided by the Michigan State Police.

Wayne County has the most crashes involving drugs, with 3,478 for the decade. Oakland County is next with 2,368, followed by Macomb County with 1,817. Those three counties are the most populated in the state, most likely attributing to their higher numbers. Genesee County, with 954, is next, followed by Kent County with 693.

2. Some of the increase in numbers could be due to better-trained officers. The rise is also likely due to more drug use, said Wes Evans, a Grand Blanc Township police officer and certified Drug Recognition Expert (DRE).

"I think it's both," he said. "Part of it's the increased usage of not only street drugs but also diverted prescription drugs."

Search a database of 2006 to 2015 Michigan crashes marked "drugs involved:"

3. Michigan is home to 99 police officers credentialed as Drug Recognition Experts. DREs, like Evans, are called to further investigate drivers suspected of being impaired but still pass a preliminary breath test.

There were a few DREs in the state beginning in 2005, Evans said, and Michigan was the 47th state to adopt the DRE program for officers across the state in 2010. Training includes 72 classroom hours plus homework and focuses on identifying people impaired by drugs.

Credentialing involves officers performing drug impairment checks on volunteers from a jail facility, who are given a urine test to confirm whether the volunteer was on drugs, and if the applicant identified the same class of drug the person was on.

4. Police officers authoring a UD-10 crash report who are not Drug Recognition Experts can mark the form as drugs involved, according to the crash report manual.

"Usually when go to a traffic crash that's under investigation (for impairment) and no alcohol is involved, then it's drugs," Special Lt. David Kaiser of the Michigan State Police said.

The opinion of the officer determine impairment can be based on appearance, behavior, smells, and other factors, Kaiser said.

"It comes down to impairment," he added.

Kaiser said people can get in trouble for driving impaired by drugs they are prescribed or believe they are taking legally, like medical marijuana.

Non-DRE patrol officers investigating a crash or traffic stop may choose to call on an available DRE to investigate when a person's blood alcohol level does not match their level of impairment noted by an officer during a traffic stop or crash, Evans said.

5. 2,143 Michigan officers have been trained through ARIDE since 2009. Advanced Roadside Impaired Driving Enforcement (ARIDE) training began in Michigan in 2009 as a way to "address the gap" in training between Standardized Field Sobriety Testing that all officers receive and the Drug Recognition Expert (DRE) training, according to the Office of Highway Safety Planning, which administers the program.

6. Annual crashes involving drugs are up while total crashes are down over the past decade. The 18,587 crashes involving drugs equal less than 1 percent of all crashes. A total of 2,977,064 traffic crashes were recorded over the decade including 105,504 alcohol-related crashes.

Total annual crashes over the decade fell by 7 percent, from 315,978 to 296,929, while crashes involving alcohol fell 24 percent, from 12,644 in 2006 to 9,523 in 2015.

Alcohol, which is not included in the drug figures, remains one of the most common substances Evans said he sees people impaired by while driving. Prescription drugs, which span several drug categories, are also common, as well as the drug categories of marijuana, central nervous stimulants like methamphetamine and narcotic analgesics, including heroin, he said.

7. New drug reporting started this year. Some records from 2006 to 2015 indicate that a blood test or urine test was administered, and others do not.

Michigan State Police spokeswoman Shanon Banner said, in past years through 2015, officers were not required to complete the "drugs involved" field.

Changes made to the UD-10 in 2016 require officers to mark "pending results" or enter a value. The improvements to reporting, she said, will allow the MSP to capture more complete data in regard to alcohol and drug-involved crashes.

The aggregate data from crash reports does not indicate what drugs were involved in each crash. The most recent year of data is based on a snapshot of a live database obtained from the Michigan State Police in March 2016.

Banner said there are indications of a significant increase in traffic fatalities in Michigan for 2015 that will be known when final figures are released in about a month.

"Given that more people are dying in vehicle crashes, everyone should be concerned," Banner said. "Whether it be drugged driving, drunk driving, aggressive driving, or distracted driving, these are all dangerous behaviors that have the potential to take your life or someone else's life."

The numbers come as a Michigan lawmaker is pushing for roadside testing for drugs, with a bill that was introduced on July 1, 2015, passing the Senate in January.

The bill, which would create a yearlong pilot program in five Michigan counties, is now at the Committee on Judiciary, where it was referred March 22 for a second reading.

Brad Devereaux is a public safety reporter for MLive.com. Follow him on Twitter and Facebook.

Data Mine is a regular feature by MLive that examines data relevant to Michigan.

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