The bill amends Chapter 31-27 of the General Laws, which pertains to motor vehicle offenses, specifically focusing on driving under the influence (DUI) of intoxicating substances. It revises the penalties for DUI offenses, including the introduction of mandatory ignition interlock system installation for varying periods depending on the offense level. For a first offense with a BAC of .08% but less than .1%, or presence of a controlled substance, the bill requires a license suspension of 30 to 180 days, followed by a six-month period of operating only vehicles equipped with an ignition interlock system. The bill also includes insertions that mandate the installation of an ignition interlock system after an initial license suspension and adjusts the periods for which the system is required based on the offender's BAC levels.

Furthermore, the bill outlines additional penalties for driving with a suspended, revoked, or canceled license due to prior DUI offenses, with a felony charge punishable by up to three years in prison and a fine of up to $3,000. It also specifies conditions for individuals under the age of eighteen, including community restitution and mandatory alcohol or drug education and/or treatment. The bill changes the language from "may" to "shall" in requiring an ignition interlock system for those under the influence of both drugs and alcohol. It introduces a new "Ignition Interlock System Fund" to assist indigent defendants and makes it a misdemeanor to tamper with an ignition interlock system. The bill includes insertions and deletions to reflect these changes, with insertions specifying new minimum and maximum periods for the ignition interlock system requirement and deletions removing previous language that allowed for more discretion in sentencing.