The National Bridge Inspection Standards (NBIS) requires bridge inventory and inspection data to be maintained for all structures over 20 feet face to face of abutments on roads maintained by public agencies that are open to the public. The data is collected to insure public safety and to provide information that helps to determine federal funding for replacement and rehabilitation of bridges. There are approximately 8000 of these structures on state and toll way routes and over 17,000 on local agency roads in Illinois. The Illinois Department of Transportation (IDOT) database of this information is called the Illinois Structure Information System (ISIS).

To fulfill the NBIS requirements, the Department relies on local roads and streets agencies to collect and report inventory and inspection data for their structures. A county or municipality, using standard IDOT forms, provides the information to its respective district Bureau of Local Roads and Streets office. The data reported includes periodic field condition and safety appraisals and occasional changes to the basic inventory for each in-service bridge as well as the inventorying of each new structure built. Once IDOT receives the data it is keyed into the lSIS.

To make the bridge data more accessible and useable to its engineers and inspectors, the Department has developed a database application utilizing Microsoft Access® that contains the ISIS data. This application is called "SIMS", or "Structures Information Management System". SIMS has been modified for use by counties and other interested Illinois local agencies under the name "SIMS-County". This data may be used to aid highway planning and programming, bridge inspection scheduling, maintenance and load posting. MORE