Prospect Street
Carrying Prospect Street over Del-Raritan St Prk Trail
0.57 mi South of NJ 31, Mercer, New Jersey
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
Prospect Street in Mercer, New Jersey sits above 10% of rated New Jersey bridges on inventory load rating (23 t), while its 1913 build year is earlier than 94% of Mercer's recorded-year cohort (412 bridges).
Prospect Street in Mercer, New Jersey is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1913, 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:1151162
PRE-1950 · STEEL · SINGLE-SPAN · DECK-LED · ARTERIAL-ADT · STANDARD-LOAD · CAT-POOR
- PRE-1950 Pre-1950
- STEEL Steel
- SINGLE-SPAN Single span
- DECK-LED Deck-led
- ARTERIAL-ADT Arterial ADT
- STANDARD-LOAD Standard 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: Prospect Street
The Prospect Street bridge in Mercer, New Jersey carries Prospect Street over Del-Raritan St Prk Trail. It was built in 1913, making it 113 years old today. The structure is built primarily of steel and spans 1 section, stretching 10.7 meters (35 feet) end to end. Daily traffic averages 6,876 vehicles, placing it in the moderately-trafficked tier of New Jersey bridges. It is owned and maintained by Unknown.
The latest FHWA inspection records show a deck rating of 4/9, superstructure at 5/9, substructure at 6/9. 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 Prospect Street compares
Age against the county: built in 1913, earlier than 389 of Mercer's 412 bridges with a recorded construction year (94%), 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).
Prospect Street vs every rated New Jersey bridge
Inventory load rating (metric tons), FHWA NBI, this state
23 Top 90% higher than 10% 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
- 1913
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 10.7 m (35 ft)
- Deck Width
- 10.5 m (34 ft)
- Owner
- Unknown
- Avg Daily Traffic
- 6,876 vehicles/day
- Structure Number
- 1151162
Condition Analysis
- • The deck (driving surface) is in poor condition (4/9), showing advanced deterioration on the inspecting agency's 0-9 scale.
- • At 5/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • At 6/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
Prospect Street 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 Prospect Street 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 Prospect Street?
Prospect Street in Mercer, New Jersey has a deck rating of 4/9, superstructure rating of 5/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is Prospect Street inspected?
Prospect Street'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 6,876 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. Prospect Street 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 Prospect Street?
Prospect Street has an NBI inventory load rating of 22.7 metric tons.
Who is responsible for maintaining Prospect Street?
Prospect Street is owned and maintained by Unknown.
How old is Prospect Street and does age affect safety?
Prospect Street was built in 1913, making it 113 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.