Model Inventory of Roadway Elements – MIRE, Version 1.0

Superseded by MIRE Version 2.0 Report

Foreword

The development of the Model Inventory of Roadway Elements (MIRE) comes at a key point in time. Safety data are critical to making sound decisions about the design and operation of roadways. Critical safety data include not only crash data, but also roadway inventory data, traffic data, and other files. State DOT's need accurate and detailed roadway data as they develop and implement their Strategic Highway Safety Plans and look toward making safety investments that are more data driven.

Most States and local transportation agencies currently do not have all the data needed to use analysis tools such as SafetyAnalyst and the Interactive Highway Safety Design Model (IHSDM), and other procedures identified in the new Highway Safety Manual. The MIRE provides a structure for roadway inventory data that will allow State and local transportation agencies to use these analysis tools with their own data rather than relying on default values that may not reflect local conditions.

As the need for roadway inventory information has increased, new and more efficient technologies to collect roadway inventory information have emerged. However, the collected data still need a framework for the common sharing of the information. As with the Model Minimum Uniform Crash Criteria (MMUCC) effort that established a set of uniform crash data elements, definitions, and attributes that States are encouraged to adopt and has become a de facto standard, the MIRE provides an inventory of roadway data elements that addresses a similar need. The MIRE provides a structure for roadway inventory data elements through the use of common consistent definitions and attributes. Consistency is essential for making sense of aggregated data. Without consistency, it would not be possible to effectively compare results across jurisdictions and time regarding the application of safety treatments. Also, inconsistent information can result in safety efforts that are misguided, wasteful, or ineffective.

One of MIRE's intended functions has been to serve multiple roadway applications and user needs. The roadway data elements identified in MIRE were widely vetted across various user groups to ensure it met the data needs for multiple disciplines. The creation and application of this inventory will benefit not only safety but other disciplines such as operations, asset management and maintenance.

The benefits of MIRE — improved safety through the use of analytic tools and improved asset management, operations, and maintenance through the creation of a comprehensive inventory — will be realized only to the degree that transportation agencies use the resource. While the MIRE affords agencies a common framework in which to populate their roadway inventories, the task of completing these inventories still rests with the agencies responsible for building and maintaining the roads. We encourage the widespread adoption of the MIRE by these agencies as the framework for their roadway inventories.

[Signed] Michael S. Griffith
Director, Office of Safety Integration

[signed] Monique R. Evans
Director, Office of Safety Research and Development

Notice

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of the document.

Quality Assurance Statement

The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

Technical Documentation

Table of Contents

Acknowledgements

Acronyms

Introduction

• Background
• MIRE is Safety Related
• Using MIRE
• Date of Changes
• Supplemental Databases
  • Roadside Fixed Objects
  • Signs
  • Speed Data
  • Automated Enforcement Devices
  • Land Use Elements Related to Safety
  • Bridge Descriptors
  • Railroad Grade-Crossing Descriptors
  • Safety Improvements
• Summary

MIRE Elements

• I. Roadway Segment Descriptors
  • I.A. Segment Location/Linkage Elements
  • I.B. Segment Classification
  • I.C. Segment Cross Section
  • I.D. Segment Roadside Descriptors
  • I.E. Other Segment Descriptors
  • I.F. Segment Traffic Flow Data
  • I.G. Segment Traffic Operations/Control Data
  • I.H. Other Supplemental Segment Descriptors
• II. Roadway Alignment Descriptors
  • II.A. Horizontal Curve Data
  • II.B. Vertical Grade Data
• III. Roadway Junction Descriptors
  • III.A. At-Grade Intersection/Junctions
  • III.B. Interchange and Ramp Descriptors
• References
• Appendix A: Index of Elements
• Appendix B: HPMS and Tools Matrix By MIRE Elements
• Appenndix C: Supplementary SafetyAnalyst Matrix

List of Tables

• Table 1. Categories and Subcategories of MIRE Elements

List of Figures

• Figure 1a. Illustration of Cross Section, Two-Lane Roadway
• Figure 1b. Illustration of Cross Section, Multilane Divided Roadway Inventoried in Two Directions (Each Direction Inventoried Separately)
• Figure 1c. Illustration of Cross Section, Multilane Divided Roadway Inventoried in One Direction (Both Directions Inventoried Together)
• Figure 2. Illustration of Presence/Types of Bicycle Facilities
• Figure 3. Illustration of Types of Median Crossover/Left Turn Lanes
• Figure 4. Illustration of Roadside Ratings
• Figure 5. Illustration of Types of Curve Features
• Figure 6. Illustration of Types of Intersection/Junction Geometry
• Figure 7. Illustration of Intersecting Angle
• Figure 8. Illustration of Intersection/Junction Offset Distance
• Figure 9. Illustration of Circular Intersection
• Figure 10. Illustration of Types of Bicycle Facilities at Circular Intersections
• Figure 11. Illustration of Left Turn Lane Types
• Figure 12. Illustration of Positive, Negative, and Zero Offset Distance
• Figure 13. Illustration of Exclusive Left Turn Lane Length
• Figure 14. Illustration of Exclusive Right Turn Lane Length
• Figure 15. Illustration of Circular Intersection Exit and Entry Lanes
• Figure 16. Illustration of Circulatory Intersection Exclusive Right Turn Lanes
• Figure 17. IlluStration of Ramp Configurations
• Figure 18. Illustration of Types of Interchanges
• Figure 19. Illustration of Ramp Length for Freeway and Intersection Ramp Connections
• Figure 20. Illustration of Acceleration Lane Length for Tapered and Parallel Designs
• Figure 21. Illustration of Deceleration Lane Length for Tapered and Parallel Designs
• Figure 22. Illustration of Locations of Beginning Ramp Terminal Relative to Mainline Flow
• Figure 23. Illustration of Locations of Ending Ramp Terminal Relative to Mainline Flow