SR 4006 over Slippery Rock Crk.

Butler County, Pennsylvania · rated Good in the 2025 National Bridge Inventory

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

• SR 4006 over Slippery Rock Crk. in Butler County, Pennsylvania, is rated in good condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the deck, rated 8 (very good condition) on the 0-9 scale.
• It was built in 2013, making it 12 years old at the 2025 inventory.
• It carries about 231 vehicles a day (traffic count year 2024).
• Its listed owner is the state highway agency.
• It is one of 111 of the 374 inventoried bridges in Butler County rated good (29.7%); 51 (13.6%) 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 → (41.04742, -79.99764)

Component ratings

Bridge details

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

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