Safe Systems Start with Quality Data

Good data and effective analysis are key to making sound decisions on the safety, design, and operation of roadways for all road users. MIRE provides a comprehensive list of roadway and traffic data elements and accompanying data dictionary that serves as a robust inventory model to support data-driven safety decision making such as those presented in the Highway Safety Manual.

The 2012 Moving Ahead for Progress in the 21st Century Act (MAP-21) legislation called for improved and more robust safety data for better safety analysis to support the development of States’ Strategic Highway Safety Plans (SHSPs) and Highway Safety Improvement Programs (HSIPs). The Fixing America’s Surface Transportation Act (FAST Act), signed in 2015, continued the State safety data system requirements established in MAP-21.

MIRE is a recommended listing of roadway characteristic and traffic inventory elements critical to safety management and to develop comprehensive safety data systems (crash, roadway, and traffic data). MIRE helps States meet the data requirements common among analytical tools, including:

• Highway Safety Manual (HSM)
• AASHTOWare Safety (formerly Safety Analyst™)
• Crash Modification Factors (CMF) Clearinghouse
• Interactive Highway Safety Design Model (IHSDM)
• AASHTO's NCHRP Series 500 Data and Analysis Guide

The Model Inventory of Roadway Elements Version 2.1 (MIRE 2.1) is the latest guideline resulting from two decades of Federal safety data policy and national best practices. The purpose of MIRE is to provide States with a national model of relevant roadway and traffic data inventory they can use to support data-driven decision making. Consistent with other MIRE updates, MIRE 2.1 includes a revised format to reflect modern database environments, better aligns with other Federal datasets and requirements across FHWA, updates operational and design elements that have become more widely implemented and serves as a resource for meeting Federal safety data requirements.

MIRE Fundamental Data Elements

MAP-21 and the FAST Act required the Secretary to establish a subset of the MIRE that are useful for the inventory of roadway safety and ensure that States adopt and use the subset to improve data collection. [23 U.S.C. 148(f)(2)]. FHWA established a subset of the MIRE as part of the HSIP Final Rule changes to 23 CFR Part 924, effective April 14, 2016. This MIRE subset is referred to as the fundamental data elements (FDEs).

The FDEs are categorized by roadway functional classification and pavement type (non-local paved, local paved and unpaved roads). They are further refined into subcategories of data elements for roadway segments, intersections, and interchanges. The MIRE FDE provide enough data to enable jurisdictions to analyze crash experience on their roadway networks relative to the expected average crash frequency given the roadway and traffic characteristics at each location.

FHWA tiered the required FDEs for each category:

Non-Local Paved Roads

Note AADT = Annual Average daily Traffic

Local Paved Roads

Unpaved Roads

MIRE 2.0

FHWA published the initial MIRE Report in 2007 and released MIRE 1.0 with more than 200 elements in 2010. In 2018, FHWA released MIRE 2.0 as a refinement. Safety analysis techniques advanced between 2010 and 2018, with safety and data communities developing an increased awareness of the importance of good quality data in safety analysis. Additionally, new Federal requirements for data were issued, including the MIRE Fundamental Data Elements (FDE) and the Highway Performance Monitoring System (HPMS) All Road Network of Linear Referenced Data (ARNOLD). For example, the HPMS ARNOLD requirement expanded States’ obligation to include all public roads into their linear referencing system (LRS) base map. This LRS requirement provides at least one means to locate MIRE data elements geospatially.

In response to these changes, FHWA initiated a reassessment of MIRE 1.0 that resulted in MIRE 2.0. The MIRE 2.0 update included a revised format to reflect:

• The transition from isolated datasets to enterprise database environments among agencies;
• Alignment with other Federal datasets and requirements across FHWA; and
• Updates to operational and design elements that have become more widely implemented.

MIRE 2.0 served as a resource for meeting Federal safety data requirements of the time.

Resources

MIRE & Supporting Documents

• Model Inventory of Roadway Elements (MIRE) 2.1
• Model Inventory of Roadway Elements - MIRE 2.0
• MIRE Data Collection Guidebook
• Performance Measures for Roadway Inventory Data
• Model Performance Measures for State Traffic Records Systems
• Development of a Structure for a MIRE Management Information System

MIRE FDE

• MIRE FDE Graphic
• Model Inventory of Roadway Elements: An In-Person Peer Exchange 2023
• Guidance on State Safety Data Systems
• Background Report: Guidance for Roadway Safety Data to Support the Highway Safety Improvement Program
• MIRE and MIRE FDE Technical Assistance: Final Report

Tools

• AASHTOWare Safety
• FHWA Interactive Highway Safety Design Model (IHSDM)
• Highway Safety Manual
• Roadway Data Extraction Tool User Guide
• Roadway Data Extraction Tool Implementation and Programming Guide

Databases

• FHWA Highway Performance Monitoring System
• Highway Safety Information System (HSIS)

Scan Reports

• Traffic Safety Information Systems in Europe and Australia
• Traffic Safety Information Systems International Scan: Strategy Implementation White Paper

Other Resources

• Model Minimum Uniform Crash Criteria (MMUCC)
• FHWA Office of Asset Management
• USDOT Traffic Records Coordinating Committee
• Association of Transportation Safety Information Professionals (ATSIP)

ARCHIVE Resources

• Model Inventory of Roadway Elements - MIRE 1.0
• Model Minimum Inventory of Roadway Elements (MMIRE)
• MIRE MIS Lead Agency Data Collection Report
• MIRE Element Collection Mechanisms and Gap Analysis
• The Exploration of the Application of Collective Information to Transportation Data for Safety

Contact Us

Dr. Carol Tan
Federal Highway Administration
Office of Safety Research and Development
carol.tan@dot.gov

Sarah Weissman Pascual
Federal Highway Administration
Office of Safety Programs
sarah.pascual@dot.gov

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