Bridge conditions in Ketchikan Gateway Borough, Alaska
107 inventoried bridges · 12 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Of the 107 Ketchikan Gateway Borough bridges in the federal inventory, 12 carry a poor rating. That 11.2% share is roughly 2x the national average.
- 12 of the 107 bridges in Ketchikan Gateway Borough, Alaska, are rated in poor condition (11.2%) in the 2025 National Bridge Inventory, as of .
- 50 bridges (46.7%) are rated good and 45 (42.1%) fair.
- The median Ketchikan Gateway Borough bridge was built in 1997.
- The busiest poor-rated bridge is South Tongass Hwy over Water St Viaduct (built 1955), carrying about 14,046 vehicles a day.
Good 46.7% · Fair 42.1% · Poor 11.2% of 107 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| South Tongass Hwy over Water St Viaduct | 1955 | 14,046 | Poor |
| South Tongass Hwy over Hoadley Creek | 1957 | 11,900 | Poor |
| North Tongass Hwy over Ward Creek | 1975 | 5,250 | Poor |
| Park/harris St over Ketchikan Creek | 1957 | 2,512 | Poor |
| Shelter Cove Road over Harriet Hunt Creek | 1981 | 125 | Poor |
| Sayles/gorge St over Sayles/gorge Viaduct | 1960 | 40 | Poor |
| Harding Street over Harding Street | 1968 | 30 | Poor |
| Peterson Street over Peterson Street | 1955 | 30 | Poor |
| 8400000 over Trail # 828400SHOAL | 1992 | 5 | Poor |
| No Data Entered over Perm | 1997 | 2 | Poor |
| No Data Entered over Mod | 1989 | – | Poor |
| 8330000 over Mod | 1992 | – | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| South Tongass Hwy over Tongass Avenue Viaduct | 1956 | 14,564 | Fair |
| South Tongass Hwy over Water St Viaduct | 1955 | 14,046 | Poor |
| South Tongass Hwy over Hoadley Creek | 1957 | 11,900 | Poor |
| North Tongass Hwy over Carlanna Creek | 1973 | 9,210 | Fair |
| South Tongass Hwy over Front Street Viaduct | 1969 | 8,330 | Fair |
| South Tongass Hwy over Ketchikan Creek | 1944 | 6,850 | Fair |
| South Tongass Hwy over Front and Mill St Viad | 1973 | 6,830 | Good |
| North Tongass Hwy over Cannery Creek | 1989 | 5,280 | Fair |
| North Tongass Hwy over Ward Creek | 1975 | 5,250 | Poor |
| North Tongass Hwy over Whipple Creek | 1968 | 3,440 | Fair |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of Alaska: Alaska bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.