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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation
FHWA Highway Safety Programs

Model Inventory of Roadway Elements (MIRE)

MIRE is a recommended listing of roadway characteristic and traffic inventory elements critical to safety management. MIRE is a guide to help transportation agencies improve their roadway and traffic data inventories. It was developed to support a State's advanced safety analyses such as presented in the Highway Safety Manual.

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. MIRE provides a basis for a robust data inventory and helps agencies create performance measures to assess data quality.

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 can help States achieve a robust roadway and traffic data inventory as part of each State’s safety data system (crash, roadway, and traffic data). MIRE helps States meet the data requirements common among analytical tools, including:

About MIRE
Integrating MIRE
MIRE 2.0

About MIRE

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. MIRE is a recommended guideline of data elements that States could collect to develop a comprehensive roadway and traffic data inventory for safety management.

To get the maximum benefit from adopting MIRE, safety data should be recorded using a common geospatial location referencing system (e.g., linear referencing system, latitude/longitude). Thus, transportation agencies will be able to link safety data and other types of data, making it easier to collect, store, integrate, and use all types of data.

Safety First

Having these additional data can help better identify where the safety problems are, what those problems are, and how best to treat them. These integrated data sets will provide agencies with the ability to:

Benefits of MIRE beyond Safety: Taking Transportation Data to the Next Level

Expanding roadway inventories with MIRE elements offers additional benefits beyond safety. By adopting MIRE, agencies will have an extended, connected, and interoperable spatial database. Practical benefits beyond safety include:

  • Coordinating design, construction, maintenance, safety, and asset management activities.
  • Improving State, local, and Tribal geospatial addressing methods.
  • Supporting BIM/CIM and other advanced techniques.

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Integrating MIRE

Data-Driven Decisions Using Quality Data Saves Lives

Integrating quality roadway and traffic data with crash data helps agencies make better decisions and use limited resources more effectively. Establishing a roadway Management Information System (MIS)  using MIRE as a framework helps States integrate their safety data and prepare for advanced safety analyses.

Between 2011 and 2013, FHWA conducted a MIRE MIS project exploring ways to incorporate MIRE data into States’ MIS. The project delivered documentation for data collection, handling, and storage processes and described methods and metrics for assessing MIRE data quality and MIS performance. The MIRE MIS provides lessons on how to collect, integrate, manage, and measure data for improved safety decision making. The MIRE MIS series includes:

  • Data collection
    • MIRE Element Collection Mechanisms and Gap Analysis (FHWA-SA-11-49): This report presents the findings of an effort to explore existing and emerging data collection technologies and to narrow the gaps between the elements in the MIRE listing and the data available from transportation agencies' inventories and supplemental databases circa 2011. The report provides data managers and data collectors with potential techniques for advancing future collection of roadway and traffic inventory data.
    • MIRE Management Information System Lead Agency Data Collection Report (FHWA-SA-13-008): This report presents the findings from feasibility tests of methods for collecting the MIRE intersection data elements by using two different data extraction methods. The implications from this effort may lead to more effective and efficient methods of increasing the collection and use of MIRE by State and local transportation agencies and may better assist States in complying with the guidance and requirements of the Fixing America’s Surface Transportation Act (FAST Act).
    • White PaperThe Exploration of the Application of Collective Information to Transportation Data for Safety (FHWA-SA-13-006): Collective information is a technique for assembling or gathering information on a subject through the use of a large, diverse, and potentially unstructured group of individuals. This white paper explores the use of collective information as a means of gathering the data needed for transportation safety improvements and potential next steps for using this method to support the collection of transportation data.
    • MIRE Data Collection Guidebook (FHWA-SA-13-009): The guidebook builds on the MIRE Version 1.0 document by identifying issues States should be aware of when collecting specific MIRE elements. The guidebook discusses methods for collecting MIRE elements and the potential limitations of those methods
  • Data Handling, Storage and File Structure
    • Development of a Structure for a MIRE Management Information System (FHWA-SA-13-007) This report identifies issues States should be aware of when collecting, correcting, and maintaining information for a safety management information system. The report presents a conceptual model that identifies the business functions of a State safety management information system. The document provides data managers with information and issues they should consider when integrating safety data to support advanced analyses.
  • Data Quality Performance Measures

Customizing MIRE to Your Database

In addition to the MIRE FDE (discussed below), States should take what is useful in MIRE and apply it in a way that helps improve their inventory and improves data-driven decision making.

When selecting MIRE elements States should consider what questions they are trying to answer and what types of analyses they expect to conduct to answer those questions. The MIRE elements are geared towards an agency’s safety management needs. Additionally, MIRE does not include all types of data or databases that a State may want to consider collecting or integrating into analyses. States are encouraged to add additional items critical to their unique safety analyses and needs.

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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. 

MIRE publication covers

Since the release of MIRE 1.0 in 2010, safety analysis techniques have advanced, and both the safety and data communities have developed an increased awareness of the importance of good quality data in safety analysis. Additionally, new Federal requirements for data have been 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 includes 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 also serves as a resource for meeting the above Federal safety data requirements.

MIRE Version 2.0 continues to provide a structure for roadway inventory data that will allow State and local transportation agencies to use analysis tools with their own data rather than relying on default values that may not reflect local conditions.

Moving from MIRE 1.0 to MIRE 2.0

As part of the process reassessing MIRE 1.0, FHWA:

  1. Examined and compared MIRE 1.0 to other databases used by FHWA, State, and local agencies. The internal assessment included reviewing the following data dictionaries and datasets:

    This examination led to minor changes to MIRE 1.0 to make it more consistent with these databases.

  2. Vetted the reassessment findings externally with practitioners and users of MIRE by hosting four vetting sessions with practitioners from both State and local agencies to further refine the recommended revisions.
  3. Vetted the findings with an FHWA panel to further refine and finalize the recommended revisions based upon the previous four external vetting sessions.

Revised Content Structure for MIRE 2.0 Data Elements

The FHWA MIRE project team condensed the MIRE 1.0 categories and subcategories of elements into six simplified data types in MIRE 2.0 to better reflect how an agency would manage MIRE data in a more integrated database environment.

Data Type Number of MIRE Elements
Segment 109
Intersection 28
Intersection Leg 40
Interchange/Ramp 25
Horizontal Curve 8
Vertical Grade 5


The Model Inventory of Roadway Elements (MIRE) 2.0 Report explains the process and the findings of the reassessment process in further detail.

"Data Type/MIRE Elements. Each MIRE element contains a name, indicator if an FDE, Definition, Recommended attributes, Crosswalk table, and illustration"

The MIRE 2.0 report provides the following information for each one of the 205 MIRE 2.0 elements:

  • NAME

"Example representation of an element in the MIRE 2.0: Number of Through Lanes (FDE). Definition, Recommended Attributes, Crosswalk table all included""

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  • Model Inventory of Roadway Elements MIRE 2.0 – Provides a list of MIRE Version 2.0 recommended elements and attributes.
  • Webinar: “MIRE FDE & MIRE 2.0: What You Need to Know” – Provides information about the updated process and changes from MIRE 1.0 to MIRE 2.0, an update on the requirements and status of the MIRE FDEs, and information about FHWA technical assistance available to help States improve MIRE data and meet MIRE FDE requirements.
  • RSDP Toolbox – Contains resources to help agencies build a new or strengthen an existing roadway safety data program, including how to manage, analyze, and collect data.
  • MIRE Data Collection Guidebook – Discusses methods of collecting the MIRE elements and potential limitations of those methods.
  • MIRE Element Collection Mechanisms and Gap Analysis – Presents the findings of an effort both to explore existing and emerging data collection technologies as well as to narrow the gaps between the elements in the MIRE listing and the current data available from transportation agencies' inventories and supplemental databases.
  • MIRE MIS Lead Agency Data Collection Report – Presents the findings from an effort to assist two States in expanding their roadway inventory data collection to include MIRE intersection data elements. Documents two different methods of data extraction used by the two pilot states.




Scan Reports

Other Resources

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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 surface type and include three categories for roadway segments, one each for non-local paved roads, local paved roads, and unpaved roads They are further refined, for non-local paved roads, into subcategories of data elements for intersections and interchanges.

FHWA developed a set of interactive graphic images to depict the MIRE FDEs for each of the roadway categories.  By clicking on one of the roadway categories boxes at the top of the screen, a sample graphic image appears for that category (e.g. segment, intersection and interchange).  There are three categories of road segments (e.g. non-local paved road, local paved road, unpaved road), clicking in the box associated with that category changes the screen to a graphic depiction of that category.  Within each graphic image, the bottom middle of the image provides a set of tabs with data element names on them, placing the cursor over a data element name tab and clicking produces the data element name, element definition, and attributes suggested to describe the data element.  Also, the roadway graphic visually depicts the element and provides sample information that could be collected to describe that data element within a roadway inventory database.

If you encounter any difficulties or would like additional information regarding the MIRE FDE graphics, please contact Sarah Weissman Pascual at:, 202-366-0087.

Both MAP-21 and the FAST Act required the Secretary to establish a subset of MIRE and ensure that States adopt and use that subset for improved data collection. The HSIP and Safety Performance Management Measures (Safety PM) Final Rules that FHWA published in 2016 updated the existing HSIP requirements to be consistent with MAP-21 and the FAST Act. The final rules also defined this subset of the MIRE, known as the MIRE Fundamental Data Elements (MIRE FDE). 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.

Recognizing the challenges States would face in collecting all 37 elements on all public roads, FHWA tiered the FDEs based on functional class and surface type. This tiered system has three categories:

Road Category Number of Required MIRE-
FDE Elements
Non-local paved roads 37
Local paved roads 9
Unpaved roads 5

The FDE for non-local paved roads are further categorized into data elements for roadway segments, intersections, and interchanges/ramps.

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Non-Local Paved Roads

Roadway Segment

Segment Identifier (12)

Route Number (8) Route/Street Name (9)
Federal Aid/Route Type (21) Rural/Urban Designation (20) Surface Type (23)
Begin Point Segment Descriptor (10) End Point Segment Descriptor (11) Segment Length (13)
Direction of Inventory (18) Functional Class (19) Median Type (54)
Access Control (22) One/Two-Way Operations (91) Number of Through Lanes (31)
AADT (79) AADT Year (80) Type of Govermental Ownership (4)

Unique Junction Identifier (120)

Location Identifier for Road 1 Crossing Point (122)

Location Identifier for Road 2 Crossing Point (123)

Intersection/Junction Geometry (126)

Intersection/Junction Traffic Control (131)

AADT [for each intersecting road] (79)

AADT Year [for each intersecting road] (80)

Unique Approach Identifier (139)


Unique Interchange Identifier (178)

Location Identifier for Roadway Beginning Ramp Terminal (197)

Location Identifier for Roadway Ending Ramp Terminal (201)

Ramp Length (187)

Roadway Type at Beginning Ramp Terminal (195))

Roadway Type at Ending Ramp Terminal (199)

Interchange Type (182)

Ramp AADT (191)

Year of Ramp AADT (192)

Functional Class (19)

Type of Governmental Ownership (4)


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Local Paved Roads

Roadway Segment

Segment Identifier (12)

Functional Class (19)

Surface Type (23)

Type of Governmental Ownership (4)

Number of Through Lanes (31)

Annual Average Daily Traffic (79)

Begin Point Segment Descriptor (10)

End Point Segment Descriptor (11)

Rural/Urban Designation (20)

Unpaved Roads

Roadway Segment

Segment Identifier (12)

Functional Class (19)

Type of Governmental Ownership (4)

Begin Point Segment Descriptor (10)

End Point Segment Descriptor (11)


Note AADT = Annual Average daily Traffic

The number in parentheses refers to the MIRE number in MIRE 1.0.

Contact Us

Carol Tan
Federal Highway Administration
Office of Safety Research and Development

Sarah Weissman Pascual
Federal Highway Administration
Office of Safety Programs

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