Structure 701450010600 · Hillsborough County, NH
Carries Thorntons Ferry RD over Beaver Brook, 3.2 Mi Fr Merrimack Tl.
A culvert 20 ft across with 2 openings. Lengths are drawn to scale; at this length a semi-truck would be a speck. Each part is colored by its latest inspection rating. The inventory records lengths but not heights, so those are drawn as typical for a culvert.
| State | New Hampshire |
| County | Hillsborough |
| Location | 3.2 Mi Fr Merrimack Tl |
| Carries | Thorntons Ferry RD |
| Crosses | Beaver Brook |
| Coordinates | 42.85892, -71.61628 |
| Material | Steel |
| Design | Culvert |
| Total Length | 20.0 ft (6.1 m) |
| Max Span | 8.9 ft (2.7 m) |
| Deck Area | 37.2 sq m |
| Main Spans | 2 |
| Year Built | 1970 |
| Avg Daily Traffic | 356 (2023) |
| Truck Traffic | 4% |
| Lanes On Bridge | 2 |
| Last Inspection | June 2024 |
| Inspection Frequency | Every 16 months |
| Owner | City/Municipal Highway Agency |
| Historical Significance | Bridge is possibly eligible (requires evaluation) |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | 000701450010600 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.