Millstone Road
Carrying Millstone Road over Millstone River
0.5 MI N.OF COUNTY RT 615, Mercer, New Jersey
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
Millstone Road in Mercer, New Jersey is rated Poor in the FHWA's 2024 National Bridge Inventory.
Built in 1967, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. 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 NJ:1107604
INTERSTATE-ERA · STEEL · SINGLE-SPAN · TIED-CTRL · ARTERIAL-ADT · HEAVY-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- STEEL Steel
- SINGLE-SPAN Single span
- TIED-CTRL Tied control
- ARTERIAL-ADT Arterial ADT
- HEAVY-LOAD Heavy 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: Millstone Road
The Millstone Road bridge in Mercer, New Jersey carries Millstone Road over Millstone River. It was built in 1967, making it 59 years old today. The structure is built primarily of steel and spans 1 section, stretching 25.6 meters (84 feet) end to end. Daily traffic averages 8,430 vehicles, placing it in the moderately-trafficked tier of New Jersey bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 4/9, superstructure at 5/9, substructure at 4/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed.
How Millstone Road compares
Age against the county: built in 1967, earlier than 286 of Mercer's 412 bridges with a recorded construction year (69%), 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 Jersey bridges with a recorded inventory load rating (6,826 of 6,827 rated).
Millstone Road vs every rated New Jersey bridge
Inventory load rating (metric tons), FHWA NBI, this state
54 Top 25% higher than 75% of 6,826 bridges
rated New Jersey 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.
Mercer inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 414 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
- 1967
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 25.6 m (84 ft)
- Deck Width
- 11.7 m (38 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 8,430 vehicles/day
- Structure Number
- 1107604
Condition Analysis
- • The deck (driving surface) rates poor at 4/9, with advanced deterioration recorded on the latest inspection.
- • At 5/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • The substructure (piers and abutments) rates poor at 4/9, with advanced deterioration recorded on the latest inspection.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
Millstone Road 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 Millstone Road against other structures in Mercer and across New Jersey. New Jersey 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 Millstone Road?
Millstone Road in Mercer, New Jersey has a deck rating of 4/9, superstructure rating of 5/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is Millstone Road inspected?
Millstone Road'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 8,430 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. Millstone Road 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 Millstone Road?
Millstone Road has an NBI inventory load rating of 53.5 metric tons.
Who is responsible for maintaining Millstone Road?
Millstone Road is owned and maintained by County Highway Agency.
How old is Millstone Road and does age affect safety?
Millstone Road was built in 1967, making it 59 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.
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.