NH 1B
Carrying NH 1B over LITTLE HARBOR
1.1 MI JCT RT 1-A, Rockingham, New Hampshire
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
NH 1B in Rockingham, New Hampshire sits above 5% of rated New Hampshire bridges on inventory load rating (15 t), while its 1942 build year is earlier than 81% of Rockingham's recorded-year cohort (308 bridges).
NH 1B in Rockingham, New Hampshire is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1942, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 3. The lowest applicable rating sets the federal condition category, so this Poor result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure NH:018100660007100
PRE-1950 · STEEL · SINGLE-SPAN · SUPER-LED · ARTERIAL-ADT · LIGHT-LOAD · CAT-POOR
- PRE-1950 Pre-1950
- STEEL Steel
- SINGLE-SPAN Single span
- SUPER-LED Superstructure-led
- ARTERIAL-ADT Arterial ADT
- LIGHT-LOAD Light load
- CAT-POOR Poor
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: NH 1B
The NH 1B bridge in Rockingham, New Hampshire carries NH 1B over LITTLE HARBOR. It was built in 1942, making it 84 years old today. It was last reconstructed in 1975, extending its service life. The structure is built primarily of steel and spans 1 section, stretching 77.3 meters (254 feet) end to end. Daily traffic averages 3,283 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 3/9, substructure at 4/9. The weakest component sits in poor condition. Because at least one major component scores 4 or lower, this bridge falls in FHWA's Poor condition category. That category is not a closure order.
How NH 1B compares
Age against the county: built in 1942, earlier than 248 of Rockingham's 308 bridges with a recorded construction year (81%), against a county median build year of 1981. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across New Hampshire bridges with a recorded inventory load rating (2,540 of 2,542 rated).
NH 1B vs every rated New Hampshire bridge
Inventory load rating (metric tons), FHWA NBI, this state
15 Top 95% higher than 5% of 2,540 bridges
rated New Hampshire bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Rockingham inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 308 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1942
- Last Reconstructed
- 1975
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 77.3 m (254 ft)
- Deck Width
- 9.4 m (31 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 3,283 vehicles/day
- Structure Number
- 018100660007100
Condition Analysis
- • The deck (driving surface) rates fair at 6/9, minor deterioration that routine maintenance should address.
- • The superstructure (beams and supports above the deck) is in poor condition (3/9), showing advanced deterioration on the inspecting agency's 0-9 scale.
- • The substructure (piers and abutments) is in poor condition (4/9), showing advanced deterioration on the inspecting agency's 0-9 scale.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
NH 1B is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare NH 1B against other structures in Rockingham 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 NH 1B?
NH 1B in Rockingham, New Hampshire has a deck rating of 6/9, superstructure rating of 3/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is NH 1B inspected?
NH 1B'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 3,283 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. NH 1B is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for NH 1B?
NH 1B has an NBI inventory load rating of 15.3 metric tons.
Who is responsible for maintaining NH 1B?
NH 1B is owned and maintained by State Highway Agency.
How old is NH 1B and does age affect safety?
NH 1B was built in 1942, making it 84 years old and last reconstructed in 1975.
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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.