Griffin Mill Road over Maple Falls Brook
Rockingham County, New Hampshire · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Griffin Mill Road over Maple Falls Brook in Rockingham County, New Hampshire, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 1 (imminent failure condition) on the 0-9 scale.
- It was built in 1850 and reconstructed in 1991, making it 175 years old at the 2025 inventory.
- It carries about 208 vehicles a day (traffic count year 2023).
- Its listed owner is a city or municipal highway agency.
- It is one of 22 of the 309 inventoried bridges in Rockingham County rated poor (7.1%); 22 (7.1%) 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 September 2024, on a 16-month routine inspection cycle.
- 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 → (43.0056, -71.34909)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 1 | 1 | Imminent failure condition |
| Superstructure | 1 | 1 | Imminent failure condition |
| Substructure | 1 | 1 | Imminent failure condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 28 ft |
| Location | 300 Yds N. of Nh 121 |
| NBI structure number | 001300950012700 |
| Condition class | Poor |
| Traffic status (item 41) | Closed to all traffic |
| Last inspection (item 90) | September 2024 |
| Inspection interval (item 91) | 16 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the New Hampshire department of transportation.
Busiest bridges in Rockingham County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-95 over Access Road | 1950 | 86,429 | Fair |
| I-95 over Maplewood Avenue | 1970 | 76,465 | Fair |
| I-95 over Preble Way CSX | 1971 | 74,766 | Fair |
| I-95 over Piscataqua River | 1971 | 74,766 | Fair |
| I-95 over Market Street | 1970 | 70,573 | Good |
| US 4 Nh 16 Sp Tpk over Shawayttuck | 1983 | 68,236 | Good |
All bridges nearby: Rockingham County, NH bridge conditions · every bridge in Rockingham County · New Hampshire bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.