Model Minimum Uniform Crash Criteria (MMUCC)

To encourage greater uniformity, the National Highway Traffic Safety Administration (NHTSA) and the Governors Highway Safety Association (GHSA) cooperatively developed a voluntary data collection guideline in 1998. The MMUCC guideline identifies a minimum set of motor vehicle crash data elements and their attributes that States should consider collecting and including in their State crash data system.

Document MMUCC 5th Edition Guideline Download

MMUCC 5th Edition Guideline

The MMUCC 5th Edition is the result of an 18-month collaboration between NHTSA, the Federal Highway Administration (FHWA), the Federal Motor Carrier Safety Administration (FMCSA), the National Transportation Safety Board (NTSB), the GHSA, and subject matter experts from State DOTs, local law enforcement, emergency medical services, safety organizations, industry partners, and academia. The traffic records community and general public also contributed through external forums (Federal Register) and at the 2016 Traffic Records Forum.

Functionally, a traffic records system includes the collection, management, and analysis of traffic safety data. NHTSA Traffic Records Program Assessment Advisory (DOT HS 811 644)

The crash data system is the keystone of a State’s traffic records system. High-quality State traffic records data is critical to effective safety programming, operational management, and strategic planning. Every State – in cooperation with its local, regional, and Federal partners – should maintain a traffic records system that supports the data-driven, science-based decision-making necessary to identify problems; develop, deploy, and evaluate countermeasures; and efficiently allocate resources.

Changes to MMUCC ​

Several important changes were made in the 5th edition that provide States more flexibility, enhance data collection efforts and will improve data quality. 

  • MMUCC no longer defines how data elements should be collected (at scene/linked or derived). States are encouraged to link or derived wherever possible to minimize the impact on law enforcement.
  • Following State best practices, MMUCC now includes Fatal Crash, Large Vehicle and Hazardous Materials, and Non-Motorist crash data sections; these are only completed if applicable. The Model Minimum changes based on the circumstances instead of a one-size-fits-all approach.
  • A new type of data element—contained in the Dynamic Data Elements section—is introduced for the first time to capture data on topics that are changing rapidly. 

Frequently Asked Questions

Technical assistance is available to States through the NHTSA Crash Data Improvement Program (CDIP) and Traffic Records GO Teams. CDIP and GO Team technical assistance can be requested by submitting an application to your State’s NHTSA Regional Office. The Training and Technical Assistance application can be found here.

A State can request a MMUCC Mapping at any time by submitting an application to their NHTSA Regional Office. If your State is considering an update to its crash report or statewide crash database, MMUCC Mapping results provide decision-makers with State-to-MMUCC compatibility and the information they need to prioritize changes. The Training and Technical Assistance application can be found here.

The Mapping to MMUCC 5th Edition section of the MMUCC 5th Edition Guideline provides detailed information on the MMUCC Mapping rules and process.

There is a MMUCC Crash Report Form that can be found in Appendix C in the MMUCC 5th Edition Guideline.

A summary of changes to the MMUCC 4th Edition Guideline (2012) can be found in Appendix B of the MMUCC 5th Edition Guideline (2017).

MMUCC is a voluntary guideline that represents a minimum, model set of variables (data elements) that describe a motor vehicle crash. Data elements were incorporated into MMUCC if they were deemed necessary (needed for decision-making purposes) and comprehensive (included all aspects of the issue or problem being described).

While the MMUCC guideline is a voluntary standard designed for States to use at their discretion, specific parts of the standard have been incorporated into several regulatory requirements. States are currently required to adopt the model distracted driving data element in order to qualify for §405(e) distracted driving incentive grants. In addition, States will also be required to adopt the “serious injury (a)” attribute of the injury severity element by April 15, 2019, per FHWA’s Safety Performance Management Measures Final Rule (23 CFR 490) and NHTSA’s Uniform Procedures for State Highway Safety Grants Program Interim Final Rule (23 CFR 1300).

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MMUCC Timeline
MMUCC is generally updated every 5 years.

Since 1998, MMUCC has been updated in 2003, 2007, 2012 and 2017, with the 5th edition. The next update of MMUCC is tentatively scheduled for 2022.