Tr 503 over Otter Creek

LaSalle County, Illinois · rated Good in the 2025 National Bridge Inventory

United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled August 20, 2026

• Tr 503 over Otter Creek in LaSalle County, Illinois, is rated in good condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
• It was built in 1935 and reconstructed in 1986, making it 90 years old at the 2025 inventory.
• It carries about 1,700 vehicles a day (traffic count year 2020).
• Its listed owner is a town or township highway agency.
• It is one of 198 of the 528 inventoried bridges in LaSalle County rated good (37.5%); 75 (14.2%) are rated poor.
• A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.

View this bridge on a map → (41.16541, -88.69572)

Component ratings

Bridge details

Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.

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Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.