Bridge conditions in Belknap County, New Hampshire
112 inventoried bridges · 5 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
The federal inventory lists 112 bridges in Belknap County: 65 rated good, 42 fair, and 5 poor.
- 5 of the 112 bridges in Belknap County, New Hampshire, are rated in poor condition (4.5%) in the 2025 National Bridge Inventory, as of .
- 65 bridges (58.0%) are rated good and 42 (37.5%) fair.
- The median Belknap County bridge was built in 1965.
- The busiest poor-rated bridge is Nh 11 over Merrymeeting River (built 1934), carrying about 10,346 vehicles a day.
Good 58.0% · Fair 37.5% · Poor 4.5% of 112 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 |
|---|---|---|---|
| Nh 11 over Merrymeeting River | 1934 | 10,346 | Poor |
| Nh 11 over Poor Farm Brook | 1966 | 5,227 | Poor |
| Nh 11B over Gunstock River | 1941 | 2,690 | Poor |
| Centenary Avenue over Nhrr | 1940 | 510 | Poor |
| Brook Road over Salmon Brook | 1900 | 96 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 3 Nh 11 NH132 over I-93 | 2000 | 23,105 | Good |
| US 3 Nh 11 NH132 over Gulf Brook | 1936 | 23,105 | Fair |
| I-93 SB over NH104 NH132 | 1963 | 19,812 | Fair |
| NH106 Main St over Winnipesaukee River | 1970 | 18,507 | Fair |
| US 3 over Maple St Nhrr | 1947 | 17,943 | Good |
| US 3 Nh 11 over Winnisquam Lake | 1973 | 16,322 | Good |
| I-93 NB over NH127 | 1962 | 15,080 | Good |
| I-93 NB over NH132 | 1963 | 14,262 | Fair |
| I-93 NB over NH104 NH132 | 1963 | 14,262 | Good |
| I-93 NB over Salmon Brook | 1962 | 14,262 | Fair |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of New Hampshire: New Hampshire 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.