Structure 15000810013600 · Grafton County, NH
Carries Lyman Road over Mill Brook, 1.69 Mi NW Jct 302.
Set by its lowest-rated component: Deck and Superstructure and Substructure at 7 of 9.
How ratings work33 ft end to end, longest span 15 ft. Lengths and the car on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a rigid-frame bridge.
| State | New Hampshire |
| County | Grafton |
| Location | 1.69 Mi NW Jct 302 |
| Carries | Lyman Road |
| Crosses | Mill Brook |
| Coordinates | 44.25616, -71.89371 |
| Material | Concrete Continuous |
| Design | Frame |
| Total Length | 33.1 ft (10.1 m) |
| Max Span | 15.1 ft (4.6 m) |
| Deck Width | 27.6 ft (8.4 m) |
| Deck Area | 84.8 sq m |
| Main Spans | 2 |
| Year Built | 1926 (reconstructed 1983) |
| Avg Daily Traffic | 573 (2023) |
| Truck Traffic | 10% |
| Lanes On Bridge | 2 |
| Last Inspection | April 2024 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is possibly eligible (requires evaluation) |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | 015000810013600 |
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.