With legal marijuana sales expected to begin within a month, the commission that is supposed to make recommendations to prevent operating under the influence of marijuana and impaired driving is slated to meet for the first time Wednesday.

The Special Commission on Operating Under the Influence and Impaired Driving is expected to go over its mission and work plan Wednesday at the Arlington police station, along with a discussion of various issues related to impaired driving and testing, according to a meeting agenda.

The 13-member commission is a requirement of the state marijuana law and was tasked by the Legislature with producing "a comprehensive study relative to the regulation and testing of operating under the influence of marihuana, narcotic drugs and depressant or stimulant substances" as well as recommendations for legislation by Jan. 1, 2019.

The commission was not part of the 2016 voter law but lawmakers called for its creation in a law approved in 2017.

The commission is tasked with researching and reporting on "the scientific types of testing and data, medical types of testing and data, possible new technological forms of testing, civil liberties of the operator, social economic aspects of the testing, admissibility of evidence of impaired driving in court proceedings, burden on law enforcement, the current status of law within the commonwealth, training of law enforcement, intrusiveness of tests, cost analysis of testing, the current threshold for determining impairment, the rate of success in stopping impaired operators, and anything else" it deems necessary or significant.

The commission's membership consists of Cannabis Control Commission Executive Director Shawn Collins, who chairs the special commission by statute, attorney John Scheft (appointed by Attorney General Maura Healey), state Undersecretary for Law Enforcement Jennifer Queally (appointed by Secretary of Public Safety Daniel Bennett), State Police Detective Lt. Kenneth Halloran (appointed by State Police Col. Kerry Gilpin), Walpole Police Chief John Carmichael Jr. (representing the Mass. Chiefs of Police), Bristol County District Attorney Tom Quinn (representing the Mass. District Attorneys Association), criminal defense attorney Peter Elikann (representing the Mass. Bar Association), American Civil Liberties Union of Massachusetts representative Matt Allen, AAA Northeast representative Mary Maguire, attorney Stephanie Soriano (representing NAACP New England Area Conference), Dr. Alan Ehrlich (representing the Mass. Medical Society) and Dr. Margarita Alegria (appointed by Health and Human Services Secretary Marylou Sudders).

Collin said in March that he was still waiting for other members to be appointed before he could schedule the commission's first meeting.

"We are underway in earnest in pulling that group together to begin the process of convening and exploring that particular issue," he said March 20.

The commission is scheduled to meet Wednesday at 10 a.m. at the police station at 112 Mystic St. in Arlington.