Porter Road over Wild Ammonoosuc River
FairPosted for loadGrafton County, New Hampshire · 340 Feet FR Nh 112 · Structure no. 001801630005300
- Built
- 1849
- 176 years old, rebuilt 1999
- Condition
- Fair
- inspected October 2024
- Type
- Truss - Thru
- Wood or Timber
- Length
- 160 ft
- 2 main spans
- Daily traffic
- 529
- 2023 count
- Owner
- City
- City or Municipal Highway Agency
About this bridge
Porter Road over Wild Ammonoosuc River is a wood or timber truss - thru carrying Porter Road over Wild Ammonoosuc River in Grafton County, New Hampshire. It was built in 1849 and reconstructed in 1999, so it is 176 years old, older than the New Hampshire average of 56.9 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. Its operating status is: posted for load restriction.
It carries about 529 vehicles a day, roughly 4% of them trucks, projected to reach 782 by 2043. The structure is 160 ft (48.8 m) long and 17 ft wide. If it were closed, the detour would be 3.7 mi (6 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Porter Road over Wild Ammonoosuc River built?
It was built in 1849, making it 176 years old in 2025. It was reconstructed in 1999.
What condition is Porter Road over Wild Ammonoosuc River in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in October 2024.
How much traffic does Porter Road over Wild Ammonoosuc River carry?
About 529 vehicles per day (2023 count), of which roughly 4% are trucks.
How long is Porter Road over Wild Ammonoosuc River?
The structure is 160 ft (48.8 m) long with a longest span of 137 ft (41.8 m) and a deck 17 ft wide.
Who owns Porter Road over Wild Ammonoosuc River?
It is owned by the City or Municipal Highway Agency.