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What is MIRE?

Screenshot: MIRE Interactive page MIRE, the Model Inventory of Roadway Elements, is a recommended listing of roadway inventory and traffic elements critical to safety management. MIRE is intended as a guideline to help transportation agencies improve their roadway and traffic data inventories. It provides a basis for a standard of what can be considered a good/robust data inventory and helps agencies move towards the use of performance measures to assess data quality. The Moving Ahead for Progress in the 21st Century (MAP-21) reauthorizing legislation identifies the need for improved and more robust safety data for better safety analysis to support the development of State’s Strategic Highway Safety Plans (SHSPs) and their Highway Safety Improvement Programs (HSIPs). Among these new analytic tools are: the Highway Safety Manual, the Interactive Highway Safety Design Model (IHSDM), AASHTOWare Safety Analyst™, as well as AASHTO's NCHRP Series 500 Data and Analysis Guide, which all require crash, roadway, and traffic data to achieve the most accurate results.
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About MIRE


What are the benefits of MIRE?

Safety Benefits

There are many benefits to State and local transportation agencies expanding their roadway inventories through the adoption of MIRE elements. One of the underlying factors of the MIRE data elements is that they are all linked through a common location referencing system. By adopting MIRE, State and local transportation agencies will be able to link safety data to non-safety data, making it easier to collect, store, link, and use all types of data. 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:

  • Use new generation safety tools (Highway Safety Manual).
  • Improve States’ Highway Safety Improvement Programs (HSIP) by making more effective and efficient use of safety funds through enhanced project selection and prioritization methodologies.
  • Provide additional data to help States in their development of their Strategic Highway Safety Plans (SHSP).

Benefits of MIRE Beyond Safety

Adoption of MIRE can encourage collaboration across agencies and lead to innovative data collection techniques, promote coordination between data collection managers to reduce overlap, and provide standardized coding to help agencies better compare data across jurisdictions within their own State and with other States. These benefits extend beyond safety to:

  • Decision makers.
  • Asset management.
  • Infrastructure.
  • Operations.
  • Maintenance.

MIRE Development Efforts

FHWA refined the initial MIRE listing that resulted in the development of MIRE Version 1.0. The steps in the revisions process included:

  • Comparing the initial MIRE elements to several State databases to determine which elements States are already collecting and how the attributes and codings compare.
  • Comparing the initial MIRE elements to other databases and safety analysis tools to look for common variables and to ensure as much overlap as possible between MIRE and the other datasets.
  • Hosting web conferences to obtain additional input from eventual end users.
  • Developing a website for communicating with end users and providing a forum for additional discussion.
  • Coordinating with an Executive Steering Committee designed to provide technical input and serve as liaisons to potential users.
  • Compiling all input into refined attributes and codings for the MIRE elements.

Since the initial "MIRE" report was released in 2007, the MIRE listing has been revised and now includes over 200 elements. The MIRE listing has become more of a comprehensive listing of elements necessary for safety rather than a minimum listing. (Note MMIRE was the initial name for MIRE.)
The final report MIRE Version 1.0 was released in 2010.

MIRE Data Elements


MIRE Version 1.0 Elements

Roadway Segment Descriptors

Segment Location/Linkage Elements

  1. County Name
  2. County Code
  3. Highway District
  4. Type of Governmental Ownership
  5. Specific Governmental Ownership
  6. City/Local Jurisdiction Name
  7. City/Local Jurisdiction Urban Code
  8. Route Number
  9. Route/Street Name
  10. Begin Point Segment Descriptor
  11. End Point Segment Descriptor
  12. Segment Identifier
  13. Segment Length
  14. Route Signing
  15. Route Signing Qualifier
  16. Coinciding Route Indicator
  17. Coinciding Route — Minor Route Information
  18. Direction of Inventory

Segment Classification

  1. Functional Class
  2. Rural/Urban Designation
  3. Federal Aid/Route Type
  4. Access Control

Segment Cross Section

Surface Descriptors
  1. Surface Type
  2. Total Paved Surface Width
  3. Surface Friction
  4. Surface Friction Date
  5. Pavement Roughness/Condition
  6. Pavement Roughness Date
  7. Pavement Condition (Present Serviceability Rating)
  8. Pavement Condition (PSR) Date
Lane Descriptors
  1. Number of Through Lanes
  2. Outside Through Lane Width
  3. Inside Through Lane Width
  4. Cross Slope
  5. Auxiliary Lane Presence/Type
  6. Auxiliary Lane Length
  7. HOV Lane Presence/Type
  8. HOV Lanes
  9. Reversible Lanes
  10. Presence/Type of Bicycle Facility
  11. Width of Bicycle Facility
  12. Number of Peak Period Through Lanes
Shoulder Descriptors
  1. Right Shoulder Type
  2. Right Shoulder Total Width
  3. Right Paved Shoulder Width
  4. Right Shoulder Rumble Strip Presence/Type
  5. Left Shoulder Type
  6. Left Shoulder Total Width
  7. Left Paved Shoulder Width
  8. Left Shoulder Rumble Strip Presence/Type
  9. Sidewalk Presence
  10. Curb Presence
  11. Curb Type
Median Descriptors
  1. Median Type
  2. Median Width
  3. Median Barrier Presence/Type
  4. Median (Inner) Paved Shoulder Width
  5. Median Shoulder Rumble Strip Presence/Type
  6. Median Sideslope
  7. Median Sideslope Width
  8. Median Crossover/Left Turn Lane Type

Segment Roadside Descriptors

  1. Roadside Clearzone Width
  2. Right Sideslope
  3. Right Sideslope Width
  4. Left Sideslope
  5. Left Sideslope Width
  6. Roadside Rating
  7. Major Commercial Driveway Count
  8. Minor Commercial Driveway Count
  9. Major Residential Driveway Count
  10. Minor Residential Driveway Count
  11. Major Industrial/Institutional Driveway Count
  12. Minor Industrial/Institutional Driveway Count
  13. Other Driveway Count

Other Segment Descriptors

  1. Terrain Type
  2. Number of Signalized Intersections in Segment
  3. Number of Stop-Controlled Intersections in Segment
  4. Number of Uncontrolled/Other Intersections in Segment

Segment Traffic Flow Data

  1. Annual Average Daily Traffic (AADT)
  2. AADT Year
  3. AADT Annual Escalation Percentage
  4. Percent Single Unit Trucks or Single Truck AADT
  5. Percent Combination Trucks or Combination Truck AADT
  6. Percentage Trucks or Truck AADT
  7. Total Daily Two-Way Pedestrian Count/Exposure
  8. Bicycle Count/Exposure
  9. Motorcycle Count or Percentage
  10. Hourly Traffic Volumes (or Peak and Off-Peak AADT)
  11. K-Factor
  12. Directional Factor

Segment Traffic Operations/Control Data

  1. One/Two-Way Operations
  2. Speed Limit
  3. Truck Speed Limit
  4. Nighttime Speed Limit
  5. 85th Percentile Speed
  6. Mean Speed
  7. School Zone Indicator
  8. On-Street Parking Presence
  9. On-Street Parking Type
  10. Roadway Lighting
  11. Toll Facility
  12. Edgeline Presence/Width
  13. Centerline Presence/Width
  14. Centerline Rumble Strip Presence/Type
  15. Passing Zone Percentage

Other Supplemental Segment Descriptor

  1. Bridge Numbers for Bridges in Segment

Roadway Alignment Descriptors

Horizontal Curve Data

  1. Curve Identifiers and Linkage Elements
  2. Curve Feature Type
  3. Horizontal Curve Degree or Radius
  4. Horizontal Curve Length
  5. Curve Superelevation
  6. Horizontal Transition/Spiral Curve Presence
  7. Horizontal Curve Intersection/Deflection Angle
  8. Horizontal Curve Direction

Vertical Grade Data

  1. Grade Identifiers and Linkage Elements
  2. Vertical Alignment Feature Type
  3. Percent of Gradient
  4. Grade Length
  5. Vertical Curve Length

Roadway Junction Descriptors

At-Grade Intersection/Junctions

General Descriptors
  1. Unique Junction Identifier
  2. Type of Intersection/Junction
  3. Location Identifier for Road 1 Crossing Point
  4. Location Identifier for Road 2 Crossing Point
  5. Location Identifier for Additional Road Crossing Points
  6. Intersection/Junction Number of Legs
  7. Intersection/Junction Geometry
  8. School Zone Indicator
  9. Railroad Crossing Number
  10. Intersecting Angle
  11. Intersection/Junction Offset Distance
  12. Intersection/Junction Traffic Control
  13. Signalization Presence/Type
  14. Intersection/Junction Lighting
  15. Circular Intersection — Number of Circulatory Lanes
  16. Circular Intersection — Circulatory Lane Width
  17. Circular Intersection—Inscribed Diameter
  18. Circular Intersection—Bicycle Facility
At Grade Intersection/Junction Descriptors
(Each Approach)
  1. Intersection Identifier for this Approach
  2. Unique Approach Identifier
  3. Approach AADT
  4. Approach AADT Year
  5. Approach Mode
  6. Approach Directional Flow
  7. Number of Approach Through Lanes
  8. Left Turn Lane Type
  9. Number of Exclusive Left Turn Lanes
  10. Amount of Left Turn Lane Offset
  11. Right Turn Channelization
  12. Traffic Control of Exclusive Right Turn Lanes
  13. Number of Exclusive Right Turn Lanes
  14. Length of Exclusive Left Turn Lanes
  15. Length of Exclusive Right Turn Lanes
  16. Median Type at Intersection
  17. Approach Traffic Control
  18. Approach Left Turn Protection
  19. Signal Progression
  20. Crosswalk Presence/Type
  21. Pedestrian Signalization Type
  22. Pedestrian Signal Special Features
  23. Crossing Pedestrian Count/Exposure
  24. Left/Right Turn Prohibitions
  25. Right Turn-On-Red Prohibitions
  26. Left Turn Counts/Percent
  27. Year of Left Turn Counts/Percent
  28. Right Turn Counts/Percent
  29. Year of Right Turn Counts/Percent
  30. Transverse Rumble Strip Presence
  31. Circular Intersection—Entry Width
  32. Circular Intersection—Number of Entry Lanes
  33. Circular Intersection—Presence/Type of Exclusive Right Turn Lane
  34. Circular Intersection—Entry Radius
  35. Circular Intersection—Exit Width
  36. Circular Intersection—Number of Exit Lanes
  37. Circular Intersection—Exit Radius
  38. Circular Intersection—Pedestrian Facility
  39. Circular Intersection—Crosswalk Location (Distance From Yield Line)
  40. Circular Intersection—Island Width

Interchange and Ramp Descriptors

  1. Unique Interchange Identifier
  2. Location Identifier for Road 1 Crossing Point
  3. Location Identifier for Road 2 Crossing Point
  4. Location Identifier for Additional Road Crossing Points
  5. Interchange Type
  6. Interchange Lighting
  7. Interchange Entering Volume
  8. Interchange Identifier for this Ramp
  9. Unique Ramp Identifier
  10. Ramp Length
  11. Ramp Acceleration Lane Length
  12. Ramp Deceleration Lane Length
  13. Ramp Number of Lanes
  14. Ramp AADT
  15. Year of Ramp AADT
  16. Ramp Metering
  17. Ramp Advisory Speed Limit
  18. Roadway Type at Beginning Ramp Terminal
  19. Roadway Feature at Beginning Ramp Terminal
  20. Location Identifier for Roadway at Beginning Ramp Terminal
  21. Location of Beginning Ramp Terminal Relative to Mainline Flow
  22. Roadway Type at Ending Ramp Terminal
  23. Roadway Feature at Ending Ramp Terminal
  24. Location Identifier for Roadway at Ending Ramp Terminal
  25. Location of Ending Ramp Terminal Relative to Mainline Flow

There are a total of 202 elements that comprise the MIRE listing. These elements are divided among three broad categories: roadway segments, roadway alignment, and roadway junctions. Examples of the MIRE data elements:

  • Roadway classification
  • Paved surface characteristics
  • Number and type of travel lanes
  • Shoulder, median, and roadside descriptors
  • Curve and grade information
  • Traffic control devices
  • Intersection features
  • Interchange and ramp descriptors
  • Pedestrian and bicyclist facilities
  • Traffic volumes

Use the listing on the left to view detailed descriptions of the data elements.

A full listing of the MIRE elements is in the MIRE Version 1.0.

Supplemental Databases

The elements in MIRE are envisioned as the elements to be included in agencies’ roadway and traffic inventories. However, MIRE does not contain all inventory data needed for all safety decisions. The composition of MIRE was purposefully designed to link with supplemental databases including:

  • Roadside fixed objects
  • Signs
  • Speed data
  • Automated enforcement devices
  • Land use elements related to safety
  • Bridge descriptors
  • Railroad grade-crossing descriptors
  • Safety improvements

Integrating MIRE


Critical to the acceptance and implementation of MIRE is its conversion from a listing of variables into a Management Information System (MIS). The MIRE MIS project explored mechanisms to better incorporate MIRE data in to States’ management information systems.
The objective of the MIRE MIS effort was to test the feasibility of converting the MIRE listing into an MIS. This was done through the exploration, development, and documentation of:

  • Mechanisms for data collection.
  • Processes for data handling and storage.
  • Details of data file structure.
  • Methods to assure the integration of MIRE data with crash data and other data types.
  • Performance metrics to assess and assure MIRE data quality and MIS performance.

Data Collection

MIRE Element Collection Mechanisms and Gap Analysis
The Element Collection Mechanisms and Gap Analysis Report presents the findings of an effort to 1) explore existing and emerging data collection technologies, and 2) to narrow the gaps between the elements in the MIRE listing and the current data available from transportation agencies' inventories and supplemental databases. This report provides data managers and data collectors with potential techniques for advancing future data collection of roadway and traffic inventory data.

MIRE Management Information System Lead Agency Data Collection Report
The Lead Agency Data Collection Report presents the findings from an effort to assist two States to expand their roadway inventory data collection to include MIRE intersection data elements.  The development of this information into their databases was intended to facilitate the use of this information to use more advanced analytic methods. The report documents two different methods of data extraction used by the two pilot states. 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. Further, these results may better assist States in complying with the guidance and requirements of the Moving Ahead for Progress in the 21st Century (MAP-21) legislation.

The Exploration of the Application of Collective Information to Transportation Data for Safety White Paper
The White Paper explores the technique of collective information as a means of gathering data needed for transportation safety. Collective information is a process of assembling or gathering information on a subject through the use of a large, disperse and potentially uncontrolled group of individuals. The White Paper also examines current uses of collective information gathering and potential next steps for this process to support the collection of transportation data.

MIRE Data Collection Guidebook
The MIRE Data Collection Guidebook builds upon the MIRE, Version 1.0 document to identify issues State's should be cognizant of when collecting information on specific MIRE elements.  The Guidebook discusses methods of collecting the MIRE elements and potential limitations of those methods.  It provides data managers and collectors with information regarding techniques for collecting MIRE data elements that potentially will allow them to collect the elements more efficiently.

Data Handling, Storage and File Structure

Development of a Structure for a MIRE Management Information System
The Structure Report identifies issues State's should be cognizant of when collecting, correcting, and maintaining information for a safety management system. The report presents a conceptual model that identifies the business functions a state is likely to need from a safety management system. This document provides data managers with information and issues they should address in establishing or improving an integrated safety data file structure to enhance the safety performance of the state's roadways.

Data Quality Performance Measures

Performance Measures for Roadway Inventory Data
The Performance Measures Report builds upon NHTSA's Model Performance Measures for State Traffic Records Systems Report and identifies issues to be considered and performance measures to assess the quality of the roadway and traffic data. This report provides data managers and collectors with refined techniques for assessing the quality of the roadway and traffic data inventory data they collect and maintain.


Integrating quality roadway and traffic data with crash data helps agencies make better decisions and more effective use of limited funds to improve safety. The MIRE MIS effort provides lessons on how to collect, integrate, manage, and measure data for improved safety decision-making. State and local agencies can realize the benefits of establishing an MIS for their transportation-related data.
Better data helps lead to better decisions, which ultimately save lives!



Contact Us


Robert Pollack
Federal Highway Administration
Office of Safety Programs

Carol Tan
Federal Highway Administration
Office of Safety Research and Development

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