Denali Highway over Susitna River
Matanuska-Susitna Borough, Alaska · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Denali Highway over Susitna River in Matanuska-Susitna Borough, Alaska, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1956, making it 69 years old at the 2025 inventory.
- It carries about 60 vehicles a day (traffic count year 2020).
- Its listed owner is the state highway agency.
- It is one of 8 of the 121 inventoried bridges in Matanuska-Susitna Borough rated poor (6.6%); 8 (6.6%) are rated poor.
- Its traffic status in the 2025 inventory is open, would be posted or closed except for temporary shoring or other temporary measures (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated July 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.
- It has fracture-critical members (NBI item 92A): steel tension members without a redundant load path, which get their own scheduled inspections.
- 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 → (63.1048, -147.521)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 4 | 4 | Poor condition |
Bridge details
| Structure | Steel deck truss |
| Length | about 1,039 ft |
| Location | Mile Point 79.5 |
| NBI structure number | 0687 |
| Condition class | Poor |
| Traffic status (item 41) | Open, would be posted or closed except for temporary shoring or other temporary measures |
| Last inspection (item 90) | July 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 3: scour critical: foundations unstable for the assessed or calculated scour |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Alaska department of transportation.
Busiest bridges in Matanuska-Susitna Borough
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Parks Highway over Seward Meridian U.c. | 2005 | 32,100 | Good |
| Glenn Highway over Knik River Access U.c. | 1993 | 26,600 | Good |
| Palmer-wasill Ext over Cottonwood Overhead | 2002 | 14,000 | Fair |
| Glenn Highway over Matanuska Riv Northbound | 1965 | 13,300 | Fair |
| Glenn Highway over Knik Riv. Overflow S.B. | 1993 | 13,300 | Fair |
| Glenn Highway over Knik Riv. Overflow N.B. | 1993 | 13,300 | Fair |
All bridges nearby: Matanuska-Susitna Borough, AK bridge conditions · every bridge in Matanuska-Susitna Borough · Alaska bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.