Nh 18 over Connecticut River
PoorGrafton County, New Hampshire · Nh-Vt Sl · Structure no. 015301090013400
- Built
- 1934
- 91 years old, rebuilt 1980
- Condition
- Poor
- inspected November 2024
- Type
- Girder and Floorbeam System
- Steel
- Length
- 533 ft
- 5 main spans
- Daily traffic
- 1,508
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
Nh 18 over Connecticut River is a steel girder and floorbeam system carrying Nh 18 over Connecticut River in Grafton County, New Hampshire. It was built in 1934 and reconstructed in 1980, so it is 91 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 poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 1,508 vehicles a day, roughly 4% of them trucks, projected to reach 2,231 by 2043. The structure is 533 ft (162.5 m) long and 31 ft wide. If it were closed, the detour would be 9.9 mi (16 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Substructure | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Nh 18 over Connecticut River built?
It was built in 1934, making it 91 years old in 2025. It was reconstructed in 1980.
What condition is Nh 18 over Connecticut River in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in November 2024.
How much traffic does Nh 18 over Connecticut River carry?
About 1,508 vehicles per day (2023 count), of which roughly 4% are trucks.
How long is Nh 18 over Connecticut River?
The structure is 533 ft (162.5 m) long with a longest span of 138 ft (42.1 m) and a deck 31 ft wide.
Who owns Nh 18 over Connecticut River?
It is owned by the State Highway Agency.