NH175
Carrying NH175 over MAD RIVER
6.6 MI N JCT US 3, Grafton, New Hampshire
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: NH175
The NH175 bridge in Grafton, New Hampshire carries NH175 over MAD RIVER. It was built in 1927, making it 99 years old today. The structure is built primarily of concrete and spans 1 section, stretching 26.2 meters (86 feet) end to end. Daily traffic averages 1,912 vehicles, placing it in the moderately-trafficked tier of New Hampshire bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 6/9, substructure at 5/9. The weakest component sits in fair condition. All reported major components score above the Poor range. Its NBI inventory load rating is 19.8 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How NH175 compares
Live comparison across New Hampshire.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1927
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 26.2 m (86 ft)
- Deck Width
- 8.6 m (28 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 1,912 vehicles/day
- Structure Number
- 003501530014700
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 6/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
- • The superstructure (beams and supports above the deck) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
- • At 5/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.
How to read this record
This page shows what the last federal inspection recorded, not whether NH175 is safe to cross today. Here is how to use it.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Learn how the 0–9 condition scale and Good/Fair/Poor categories are defined. How condition ratings work
- Compare NH175 against other structures in Grafton and across New Hampshire. New Hampshire bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for NH175?
NH175 in Grafton, New Hampshire has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is NH175 inspected?
NH175's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 1,912 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. NH175 is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for NH175?
NH175 has an NBI inventory load rating of 19.8 metric tons.
Who is responsible for maintaining NH175?
NH175 is owned and maintained by State Highway Agency.
How old is NH175 and does age affect safety?
NH175 was built in 1927, making it 99 years old.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.