Illinois Department of TransportationThis item identifies a posted structure on the State system of highways for which there is a load restriction such that legally configured vehicles may not be allowed to cross the structure. The posting sign describes the maximum allowable gross weight, given in tons. Vehicles may not exceed the posted weight limit at the structure. This information is used by the trucking industry to prevent crossing these structures. This item can be obtained from http://www.gettingaroundillinois.com/ in the Designated State Truck Route System Map (including posted structures on local roadways), the Obstructions and Restrictions Map, or a listing is available for marked and unmarked routes under Resources - Oversize/Overweight at: http://www.idot.illinois.gov/doing-business/permits/Oversize-and-Overweight-Permits/index If in question, contact the Central Bureau of Urban Program Planning. For details: Structure Information and Procedures (SIP manual) The SIP manual has been developed through a cooperative effort within the Department between the O ffice of Highways Project Implementation and the Office of Planning and Programming. IDOT and its Divisions and Offices are committed to maintaining the structure information system at a high level. This commitment is not only to satisfy NBIS requirements, but also to provide an excellent working tool in managing the bridges and other structures as they relate to the overall transportation system in Illinois. In the interest of the traveling public's safety and convenience, this commitment remains a high priority for the Department.ArcGIS DynamicMapLayerhttps://hub.arcgis.com/datasets/71139434aa564a8eae8942545395e4bf_12engIllinois DOT Open Data PortalPublicState Ton Structures [Illinois]Web servicesIllinoisLast Modified: 2025-10-31