T-420 over Kish. Creek

Mifflin County, Pennsylvania · rated Poor in the 2025 National Bridge Inventory

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

• T-420 over Kish. Creek in Mifflin County, Pennsylvania, is rated in poor condition in the 2025 National Bridge Inventory (as of August 20, 2026).
• Its lowest-rated component is the superstructure, rated 0 (failed condition, out of service) on the 0-9 scale.
• It was built in 1909, making it 116 years old at the 2025 inventory.
• Its listed owner is the county highway agency.
• It is one of 23 of the 196 inventoried bridges in Mifflin County rated poor (11.7%); 23 (11.7%) are rated poor.
• Its traffic status in the 2025 inventory is closed to all traffic (NBI item 41).
• Its condition class and component ratings are unchanged from the 2024 inventory.
• Its most recent inspection on record is dated June 2023, on a 24-month routine inspection cycle.
• It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
• A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.

View this bridge on a map → (40.64869, -77.57942)

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.