Root Hill Road over Mill Brook
Sullivan County, New Hampshire · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Root Hill Road over Mill Brook in Sullivan County, New Hampshire, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1883, making it 142 years old at the 2025 inventory.
- It carries about 92 vehicles a day (traffic count year 2023).
- Its listed owner is a city or municipal highway agency.
- It is one of 79 of the 158 inventoried bridges in Sullivan County rated fair (50.0%); 9 (5.7%) are rated poor.
- 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 → (43.4644, -72.36928)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 6 | Satisfactory condition |
| Superstructure | 5 | Fair condition |
| Substructure | 5 | Fair condition |
Bridge details
| Structure | Timber through truss |
| Length | about 78 ft |
| Location | 1.3 Mi Nh 120 |
| NBI structure number | 005500810009500 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the New Hampshire department of transportation.
Busiest bridges in Sullivan County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Nh 11 NH103 over Sugar River | 1981 | 13,248 | Fair |
| Nh 11 NH103 over Sugar River | 1985 | 12,792 | Good |
| I-89 Nh 10 SB over I-89 Ramp | 1959 | 10,987 | Fair |
| I-89 Nh 10 SB over Skinner Brook | 1972 | 10,987 | Fair |
| I-89 Nh 10 SB over Miller Pond Road | 1972 | 10,987 | Good |
| I-89 SB over Nh 10 | 1972 | 10,987 | Fair |
All bridges nearby: Sullivan County, NH bridge conditions · every bridge in Sullivan County · New Hampshire bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.