“Today’s proposal includes important changes that will make Massachusetts safer,” Baker said in a news release. He added the measures will “improve how police officers train for detecting the influence of intoxicating substances like marijuana, how they interact with motorists who show signs of impairment, and eventually how these cases are tried in a courtroom.”

Under the proposals, some of which were opposed by civil liberties advocates, suspected stoned drivers who refuse police demands for a biological test would lose their driver’s licenses for at least six months , the same penalty for alleged drunk drivers who refuse a breathalyzer. The bill also calls for increasing police training to recognize drug impairment and easing the process for state troopers to cite drivers for open containers of marijuana.

Baker, who fought the 2016 ballot initiative that legalized recreational marijuana, said his administration sees these changes as “the next deliberative step” for lawmakers and regulators to safely implement legalization. Since November, nine marijuana stores have been approved for recreational sales, and more will open this year.


Lieutenant Governor Karyn Polito said the policies would raise awareness and help address the “very serious public safety concerns associated with impaired driving.”

The special commission on impaired driving — which included law enforcement officers, defense attorneys, and civil rights advocates — was formed as part of the law that legalized adult use of marijuana. Most of the commission’s 19 recommendations were passed unanimously or nearly so, with the dissenter often being the American Civil Liberties Union. The ACLU has cited research that found that marijuana does impair driving, but its danger is more akin to distracted driving and far less than that posed by drunken driving.


The commission grappled with the fact that no test exists that can measure someone’s level of impairment with marijuana the way a breathalyzer can with alcohol. There is no correlation between the level of THC, marijuana’s main psychoactive compound, in the blood and the level of impairment. Such tests are likely three to five years away, officials have said.

The ACLU opposed pressuring drivers to take the flawed biological tests because the tests would only show past marijuana use, not current impairment, leading to innocent people being punished.

“Motorists shouldn’t be faced with losing their license for refusal to submit to a test that does not measure impairment,” said Matt Allen, field director for the ACLU of Massachusetts. “In addition to being a recommendation that is not based in science or backed by evidence, it is one that could exacerbate the problem of racial disparities in enforcement.”

But law enforcement officials argued that the blood, saliva, and urine tests would be among a litany of assessments to build a case of impairment against a driver, including the officer’s observations of the driver’s traffic violations, behavior, appearance, and performance on field sobriety tests.

The proposal would also include marijuana as part of the state’s open container laws, so state troopers could more conveniently cite drivers with “unsealed” containers of marijuana, which authorities interpret as marijuana that’s not inside a trunk or locked glove box. Currently, open containers of marijuana are considered municipal offenses, officials said, so state troopers must acquire tickets from the city or town where the violation occurred.


The measure would also require adopting electronic search warrants so that officers could quickly obtain the authority to have a medical professional administer a biological test for suspected impaired drivers.

“These changes will help to bring Massachusetts into parity and ensure that the Commonwealth can protect its people from drivers who are high, just like we have long tried to protect our people from drivers who are impaired from alcohol,” Secretary of Public Safety and Security Thomas Turco said.

Cannabis Control Commissioner Jennifer Flanagan said she was happy about the bill and praised Baker’s “commitment of providing public safety officials the tools necessary to keep our communities safe.”

The bill will be assigned to a committee, debated, and given a public hearing. To pass, the final version of the bill must be approved by a majority of the House of Representatives and the Senate.

Naomi Martin can be reached at naomi.martin@globe.com. Follow her on Twitter at @NaomiMartin.