Each MMUCC data element includes a definition, a set of specific attributes and a rationale for why it is needed. Data elements are divided into four major groups that describe various aspects of a crash: crash-related, vehicle-related, person-related and roadway-related.
MMUCC consists of data elements that are recommended to be captured at the crash scene, together with linked and derived data. From the crash scene information, additional data elements can be derived, which lessens the burden on law enforcement. Additional data elements are recommended through linkage to driver history, hospital and other health/injury data, and roadway inventory data.
Each group of data elements has a unique identifier that describes what type of data element it is as well as whether it is derived or linked. Some data elements are marked with a double asterisk (**) to indicate that these elements are mandated by FMCSA for crashes involving commercial motor vehicles.
The data elements are classified into four major groups: Crash, Vehicle, Person, and Roadway.
Each group may include three different types of data elements:
- Collected: data collected by police at the scene and recorded directly onto the crash report.
- Derived: data generated from computerized crash data.
- Linked: data generated when crash data file is linked to injury, driver history, vehicle registration, roadway inventory or other data files. The format for each linked data element includes the source of the data to be linked.
Each group of data elements has a unique identifier:
- Crash data element numbers are preceded by a "C."
- Vehicle data element numbers are preceded by a "V."
- Person data element numbers are preceded by a "P."
- Roadway data element related to a crash are preceded with an "R."
Each type of data element has a unique identifier:
- Crash, Vehicle and Person data elements that are derived have the letter "D" added after the group identifier (e.g., CD, VD, PD).
- Vehicle, Person and Roadway data elements that are linked have the letter "L" added after the group identifier (e.g., VL, PL, RL).