Agencies
Services
Manuals
- The Illinois Highway Information System Roadway Info & Procedure Manual defines what, why and how roadway data is collected, and explains the individual codes used for all the roadway data provided by the Illinois Roadway Information System (IRIS).
- The Illinois Highway Information System Structure Info & Procedure Manual defines what, why, and how structure data is collected, and explains the individual codes used for all the structure data provided by the Illinois Structure Information System (ISIS).
- The Illinois Traffic Monitoring Program Manual documents the current processes and strategies used throughout the state to meet the existing traffic requirements for IDOT.