County profile · official public datasets

Hunterdon County, NJ

373 public highway bridges tracked in the FHWA National Bridge Inventory: 20.1% rated Good, 72.4% Fair, 7.5% Poor.

373
Public bridges
20.1%
Good condition
7.5%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Hunterdon County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.

15th
of 21 on Poor share
7.5%
Poor-condition share
373
public highway bridges
1949
avg year built

Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.

Hunterdon County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Hunterdon County ranks #15 of 21 New Jersey counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7.5%). Hunterdon County, New Jersey contains 373 public highway bridges. Roughly 20.1% are rated “Good,” 72.4% “Fair,” and 7.5% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.

Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

Total bridges

373

Public highway bridges in Hunterdon County

Good condition

20.1%

75 of 373 rated 7-9

Fair condition

72.4%

270 of 373 rated 5-6

Poor condition

7.5%

28 of 373 rated 4 or below

In-state Poor-share rank

#15 of 21

Among New Jersey counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 373 NBI-tracked bridges by lowest applicable component rating.

Good
20.1% (75)
Fair
72.4% (270)
Poor
7.5% (28)

Hunterdon County's Poor-condition bridges carry 205,369 vehicle crossings a day

That is 4.2% of the county's reported daily bridge traffic on 7.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 7,335 crossings a day against 6,231 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.

Computed over the 373 of 373 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

73.2% of Hunterdon County's bridges have passed the 50-year mark

273 of the 373 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 20.1% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.

Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.

One structure carries 62.4% of the county's Poor-condition bridge traffic

I-78 over BEAVER BROOK, built 1941, carries 128,249 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 28-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 205,369 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Hunterdon County's bridges were built

373 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1960s, when 57 of the county's bridges still in the inventory were built, which is 15.3% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1949, 17 years older than the New Jersey average of 1966.

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

How Hunterdon County compares with New Jersey's closest counties by inventory size

The 5 New Jersey counties nearest Hunterdon County in number of bridges, with their condition splits. Its 7.5% Poor share is the 3rd-lowest of these 6. Its average build year of 1949 against a peer-group mean of 1969 is 20 years older.

Showing the 5 closest of 20 New Jersey counties eligible for comparison.

Bridge inventory size and condition shares for Hunterdon County and the 5 New Jersey counties closest to it in inventory size
County Bridges Poor
Mercer County 414 9.2%
Union County 409 4.2%
Somerset County 397 9.6%
Hunterdon County (this page) 373 7.5%
Burlington County 356 10.1%
Passaic County 333 3.3%

Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Hunterdon County's. Source: FHWA National Bridge Inventory, 2024 release.

Nationwide counties with similar inventory size or average build year

Two NBI-derived peer sets for Hunterdon County, both outside New Jersey so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside NJ (373 bridges here).

Similar average build year

Nearest mean year-built outside NJ (1949 here).

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 373 Good 75 Fair 270 Poor 28

Poor-condition bridges (28)

MECHLIN CORNER RD

Poor

Over: Lehigh Valley ML

0.51 mi South of I-78, Hunterdon, NJ

Built 1968 Load: 2.7 t ADT: 5,144

Pine Hill Road

Poor

Over: South Br Raritan River

1.6 Miles West of NJ 31, Hunterdon, NJ

Built 1900 Load: 3.6 t ADT: 159

HAMP ROAD

Poor

Over: ALEXAUKEN CREEK

0.25 MI. WEST OF US 202, Hunterdon, NJ

Built 1900 Load: 7.3 t ADT: 67

MAIN STREET

Poor

Over: SOUTH BR RARITAN RIVER

0.1 MI WEST OF LEIGH ST, Hunterdon, NJ

Built 1870 Load: 10.0 t ADT: 403

VAN LIEUS ROAD

Poor

Over: BACK BROOK

0.8 MILE NORTH OF CR 602, Hunterdon, NJ

Built 1910 Load: 10.0 t ADT: 459

Kuhls Road

Poor

Over: Branch of Neshanic River

0.3 Mi E. of US 202-NJ 31, Hunterdon, NJ

Built 1936 Load: 10.9 t ADT: 414

MILLTOWN ROAD

Poor

Over: LOCKATONG CREEK

0.7 MILE WEST OF CR 519, Hunterdon, NJ

Built 1850 Load: 17.2 t ADT: 95

MOUNTAIN ROAD

Poor

Over: ROCKAWAY CREEK

0.9 MI WEST OF CR 517, Hunterdon, NJ

Built 1901 Load: 18.1 t ADT: 169

CHURCH ST (RT 579)

Poor

Over: LEHIGH VALLEY ML (NS)

0.53 MI South of NJ 173, Hunterdon, NJ

Built 1910 Load: 18.1 t ADT: 2,842

CORYELL STREET

Poor

Over: D&R CANAL FEEDER

.2MI N LAMBERTVILLE BRDGE, Hunterdon, NJ

Built 1949 Load: 18.1 t ADT: 1,453

MOUNTAIN ROAD

Poor

Over: RARITAN VALLEY LINE

4.42MI SE I-78 & US22 JCT, Hunterdon, NJ

Built 1910 Load: 19.1 t ADT: 520

BRIDGE STREET

Poor

Over: D&R FEEDER CANAL

0.16 MI S.of RT 29 JCT, Hunterdon, NJ

Built 1920 Load: 19.1 t ADT: 11,856

PALATINE ROAD

Poor

Over: LAMINGTON RIVER TRIB.

50 FT W. OF COLD SPR. RD., Hunterdon, NJ

Built 1900 Load: 20.0 t ADT: 216

HORSESHOE BEND RD

Poor

Over: COPPER CREEK

0.9 MI SOUTH OF NJ 12, Hunterdon, NJ

Built 1896 Load: 20.0 t ADT: 160

Changewater Road

Poor

Over: MUSCONETCONG RIVER

2.5 MI NE NJ 31, Hunterdon, NJ

Built 1900 Load: 21.8 t ADT: 1,147

COUNTY ROUTE 619

Poor

Over: HARIHOKAKE CREEK

1.9 MILES NORTH OF CR 513, Hunterdon, NJ

Built 1938 Load: 23.6 t ADT: 6,382

NEWPORT ROAD

Poor

Over: SPRUCE RUN

0.06 MI.NO OF RED MILL RD, Hunterdon, NJ

Built 1900 Load: 24.5 t ADT: 486

US 22

Poor

Over: NJT RARITAN VALLEY LINE

0.5 MI E OF I-78 JCT, Hunterdon, NJ

Built 1937 Load: 24.5 t ADT: 20,428

WOODSVILLE ROAD

Poor

Over: PETERS BROOK

100 YARDS SW OF NJ 31, Hunterdon, NJ

Built 1840 Load: 26.3 t ADT: 1,262

BRIDGE STREET

Poor

Over: D&R FEEDER CANAL

650 W OF NJ 29 MP 22.37, Hunterdon, NJ

Built 1926 Load: 27.2 t ADT: 4,726

SIDNEY RD (CR 617)

Poor

Over: Lehigh Valley ML

1.02 mi South of CR513, Hunterdon, NJ

Built 1970 Load: 29.0 t ADT: 2,770

CR 512

Poor

Over: LAMINGTON RIVER

2.5 MILES WEST OF US 206, Hunterdon, NJ

Built 1934 Load: 29.9 t ADT: 4,193

NJ 173

Poor

Over: MULHOCKAWAY CREEK

0. MI E OF CR 614, Hunterdon, NJ

Built 1919 Load: 31.8 t ADT: 4,272

THOMAS STREET

Poor

Over: HIGH BRD INDUS - ABND

2.2MI N of I78&NJ31 JCT, Hunterdon, NJ

Built 1937 Load: 37.2 t ADT: 638

LOWER KINGTOWN RD

Poor

Over: CAPOOLONG CREEK

0.5 MILE EAST OF CR 513, Hunterdon, NJ

Built 1925 Load: 39.9 t ADT: 828

CREGAR ROAD

Poor

Over: RARITAN VALLEY LINE

2.45MI N I-78 & NJ 31 JCT, Hunterdon, NJ

Built 1993 Load: 88.9 t ADT: 3,655

I-78

Poor

Over: BEAVER BROOK

1 MI EAST OF RT 31, Hunterdon, NJ

Built 1941 Load: 89.8 t ADT: 128,249

RT NJ 29

Poor

Over: COPPER CREEK

1.51 MI S OF 29-12 JCT, Hunterdon, NJ

Built 1914 Load: 99.9 t ADT: 2,376

Read our methodology - how this data is sourced, computed, and verified.

Related

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Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridges 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. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.