NH106 Main St over Winnipesaukee River
Belknap County, New Hampshire · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- NH106 Main St over Winnipesaukee River in Belknap County, New Hampshire, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1970 and reconstructed in 2015, making it 55 years old at the 2025 inventory.
- It carries about 18,507 vehicles a day (traffic count year 2023).
- Its listed owner is a city or municipal highway agency.
- It is one of 42 of the 112 inventoried bridges in Belknap County rated fair (37.5%); 5 (4.5%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated October 2024, on a 24-month routine inspection cycle.
- It has fracture-critical members (NBI item 92A): steel tension members without a redundant load path, which get their own scheduled inspections.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (43.52641, -71.46894)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous steel stringer or multi-beam girder |
| Length | about 361 ft |
| Location | 1.0 Mi Belmont T.l. |
| NBI structure number | 013901210004700 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the New Hampshire department of transportation.
Busiest bridges in Belknap 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 |
| 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 |
All bridges nearby: Belknap County, NH bridge conditions · every bridge in Belknap County · New Hampshire bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.