Illinois Department of Transportation, Erica Borggren, Acting Secretary
Patrick J. Quinn, Governor
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Illinois Highway Information System
Roadway Information & Procedure Manual
July 1, 2001
(with revisions as of November 28, 2006)

The purpose of this manual is two-fold. The first is to define what, why and how roadway data is collected. Then once information is collected, to explain when and how it is entered into the Illinois Roadway Information System (IRIS).

Table of Contents



Using the IRIS Manual

Alphabetical List of IRIS Data Items

Appendix A - Municipality List

Appendix B - Township/Road District List

Appendix C - Pavement Distress Codes

Appendix D - Abbreviation Descriptions

IRIS Manual download  2.5 mb

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