C.A.R.S. page

State Police Collision Analysis & Reconstruction Section (C.A.R.S.)


The Collision Analysis & Reconstruction Sections (C.A.R.S.) is one of the Specialized Units assigned to the Division of Field Services.  C.A.R.S. officers investigate over 500 motor vehicle crashes annually. The Section is under the direct command of a Commissioned Officer and is staffed by highly trained and professionally certified officers. C.A.R.S. is divided into four geographical teams: The Northeast, Southeast, Central, and West. These teams are arranged to provide immediate and twenty-four hour response to all areas of the Commonwealth.  

The primary mission of the Collision Analysis and Reconstruction Section is to provide technical assistance to Local, State, and Federal law enforcement agencies with their investigation of motor vehicle crashes resulting in serious injury or death. These investigations are conducted by joining the investigative skills of the primary investigator with the technical expertise of officers assigned to the C.A.R.S.

In addition to performing collision analysis, C.A.R.S. has a secondary, but equally important, mission of providing forensic mapping of non-crash related crime scenes. In creating such maps, C.A.R.S. works in partnership with officers, investigators and chemists assigned to such State Police units as the Crime Scene Services Section, the Ballistics Section, the Crime Lab, and the State Fire Marshal's office, as well as with State Police Detectives assigned to the various District Attorney Offices and personnel assigned to the Office of the Chief Medical Examiner.


Along with having highly trained and experienced personnel, C.A.R.S. officers have the most current, state-of-the-art equipment and technology further enhancing the unit's efficiency and productivity. Each C.A.R.S. officer is equipped with wireless laptop computers, a Crash Data Retrieval kit and associated software, digital cameras, digital light meters, GPS navigation equipment, photogrammetry equipment, electronic measuring devices, and much more.

Quick Clearance

C.A.R.S. officers have received additional training in the area of Quick Clearance. This is the process by which crash scenes are cleared as quickly as possible while still providing for the documentation of physical evidence that is critical to the C.A.R.S. investigation. In furtherance of Quick Clearance, C.A.R.S. works closely with other Commonwealth agencies and is represented on the Traffic Incident Management (TIM) Task Force. To ensure that C.A.R.S. officers have the necessary equipment to facilitate Quick Clearance, C.A.R.S., with the assistance of Mass DOT, has purchased nine Leica GPS mapping packages.  The Leica GPS equipment allows C.A.R.S. officers to accurately map and document crash related evidence in a very timely manner.  C.A.R.S. is one of the few law enforcement agencies in the Country to use this technology for the reconstruction of traffic crashes.  C.A.R.S. continues to purchase additional equipment to facilitate Quick Clearance.

Crash Causation / Reduction Efforts

C.A.R.S. officers assist State Police Field Troops and Local law enforcement partners to identify and develop serious Crash Causation and Reduction Initiatives. These initiatives identify the cause of collisions investigated by C.A.R.S. The collected data is analyzed based on pre-identified causation criteria. Data generated about crash causation and irresponsible driver behavior is then used in support of the Commonwealth’s commitment of minimizing the incidence of loss of life, personal injury, and property damage resulting from crashes. This data is also provided through education and training to all of our law enforcement, prosecution, and public sector partners in an effort to increase traffic safety and decrease crash frequency and severity.


C.A.R.S. in not only committed to reconstructing crashes, but is focused on understanding why crashes occur. With this knowledge, efforts can be undertaken to reduce crashes and save lives.

For further information about C.A.R.S., please send an email to carsinfo@state.ma.us

To request a copy of a reconstruction report, please send an email to cars.reports@state.ma.us  Please include the date and location of the collision as well as operator information.

Collision reconstruction reports will not be released until the conclusion of any criminal prosecution.