County profile · official public datasets

Somerset County, NJ

397 public highway bridges tracked in the FHWA National Bridge Inventory: 33% rated Good, 57.4% Fair, 9.6% Poor.

397
Public bridges
33%
Good condition
9.6%
Poor condition

The verdict

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

Somerset County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

19th
of 21 on Poor share
9.6%
Poor-condition share
397
public highway bridges
1970
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.

Somerset County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Somerset County ranks #19 of 21 New Jersey counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9.6%). Somerset County, New Jersey contains 397 public highway bridges. Roughly 33% are rated “Good,” 57.4% “Fair,” and 9.6% “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

397

Public highway bridges in Somerset County

Good condition

33%

131 of 397 rated 7-9

Fair condition

57.4%

228 of 397 rated 5-6

Poor condition

9.6%

38 of 397 rated 4 or below

In-state Poor-share rank

#19 of 21

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

Condition distribution

Share of 397 NBI-tracked bridges by lowest applicable component rating.

Good
33% (131)
Fair
57.4% (228)
Poor
9.6% (38)

Somerset County's Poor-condition bridges carry 639,320 vehicle crossings a day

That is 10% of the county's reported daily bridge traffic on 9.6% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 16,824 crossings a day against 9,020 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 397 of 397 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

54.2% of Somerset County's bridges have passed the 50-year mark

215 of the 397 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 33% 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 9.2% of the county's Poor-condition bridge traffic

I-78 EASTBOUND over I-78 RAMP "A", built 1963, carries 58,865 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 38-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 639,320 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Somerset County's bridges were built

397 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1960s, when 108 of the county's bridges still in the inventory were built, which is 27.2% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1970) matches the New Jersey average (1966).

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

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

The 5 New Jersey counties nearest Somerset County in number of bridges, with their condition splits. Its 9.6% Poor share is the 5th-lowest of these 6. Its average build year of 1970 against a peer-group mean of 1965 is 5 years newer.

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

Bridge inventory size and condition shares for Somerset 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 (this page) 397 9.6%
Hunterdon County 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 Somerset 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 Somerset County, both outside New Jersey so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside NJ (397 bridges here).

Similar average build year

Nearest mean year-built outside NJ (1970 here).

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

All 397 Good 131 Fair 228 Poor 38

All bridges (397)

PLEASANT VIEW ROAD

Good

Over: ROYCE BROOK

0.4MI S OF AMWELL RD, Somerset, NJ

Built 2003 Load: 99.9 t ADT: 616

BURNT MILLS ROAD

Good

Over: MUDDY RUN

0.58mi E. of Lamington Rd, Somerset, NJ

Built 1995 Load: 99.9 t ADT: 4,029

River Road (CR605)

Good

Over: Van Horn Brook

1 MI EAST OF US 206, Somerset, NJ

Built 2005 Load: 99.9 t ADT: 3,518

RIVER ROAD (East)

Good

Over: Trib. N. Br. Raritan R.

0.8 MI W. OF US 206/202, Somerset, NJ

Built 2014 Load: 99.9 t ADT: 530

Chimney Rock CR525

Good

Over: MIDDLE BROOK

1.3 m N of US 22, Somerset, NJ

Built 2003 Load: 99.9 t ADT: 11,646

NEWMANS LANE

Good

Over: W.BRANCH OF MIDDLE BROOK

0.6 MI SO. WASH VALLEY RD, Somerset, NJ

Built 2013 Load: 99.9 t ADT: 2,056

Pierce Street

Good

Over: Randolph Brook

0.1mi East of Randolph Rd, Somerset, NJ

Built 1988 Load: 99.9 t ADT: 542

MOUNTAIN AVENUE

Good

Over: CORYS BROOK

0.2 MI W OF SAWMILL ROAD, Somerset, NJ

Built 2011 Load: 99.9 t ADT: 4,006

VALLEY DRIVE

Good

Over: EAST BRANCH OF STONY BRK

0.05 MI E OF RT 527, Somerset, NJ

Built 1998 Load: 99.9 t ADT: 149

CAMP MEETING AVE.

Poor

Over: TRENTON LINE (CSX)

0.5 MI West of CR 601, Somerset, NJ

Built 1889 Load: 7.3 t ADT: 1,000

ROBERT STREET

Poor

Over: RARITAN CANAL

0.1 mi S of OLD YORK Rd, Somerset, NJ

Built 1931 Load: 8.2 t ADT: 100

MORTON ST.

Poor

Over: CUCKELS BROOK

.02 M S OF KLINE PL INTER, Somerset, NJ

Built 1900 Load: 12.7 t ADT: 520

HAMILTON ROAD

Poor

Over: NEW YORK BRNCH (CONRAIL)

6.1MI S OF US22&I287 JCT, Somerset, NJ

Built 1918 Load: 15.4 t ADT: 6,429

VALLEY RD (CR 512)

Poor

Over: PASSAIC RIVER

0.29 mi E of CR 651, Somerset, NJ

Built 1930 Load: 17.2 t ADT: 11,396

I-78 Eastbound

Poor

Over: Washington Valley Road

1.1 Mi East of I-287 Jct, Somerset, NJ

Built 1965 Load: 19.1 t ADT: 40,400

NEW BRUNSWICK RD

Poor

Over: TRIBUTARY TO D&R CANAL

.1 MI S OF CEDAR GROVE RD, Somerset, NJ

Built 1979 Load: 20.0 t ADT: 1,238

AMWELL RD(CR 514)

Poor

Over: DELAWARE & RARITAN CANAL

2.5 M W Cedar/Amwell Rd, Somerset, NJ

Built 1953 Load: 20.0 t ADT: 14,270

DAVENPORT STREET

Poor

Over: PETERS BROOK

0.3 MI N. OF MAIN STREET, Somerset, NJ

Built 1905 Load: 24.5 t ADT: 1,983

MAIN ST. (RT 527)

Poor

Over: DELAWARE & RARITAN CANAL

1.56 MI NORTH OF I-287, Somerset, NJ

Built 1920 Load: 24.5 t ADT: 13,520

Pottersville Road

Poor

Over: PEAPACK BROOK

0.58 MI EAST OF US 206, Somerset, NJ

Built 1927 Load: 27.2 t ADT: 3,608

I-287 SB

Poor

Over: US 22 WB+I-287 RAMP "NC"

0.85 MI N OF NJ 28 JCT, Somerset, NJ

Built 1960 Load: 29.0 t ADT: 42,223

KING GEORGE RD

Poor

Over: I-78

6.52 MI EAST OF I-287 JCT, Somerset, NJ

Built 1965 Load: 29.0 t ADT: 17,135

I-78 WESTBOUND

Poor

Over: TRIBUTARY OF DEAD RIVER

0.27 MI W / I-287 EXIT 36, Somerset, NJ

Built 1965 Load: 29.9 t ADT: 49,148

FOOTHILL ROAD

Poor

Over: I-287

0.8 MI NORTH OF US 22 JCT, Somerset, NJ

Built 1963 Load: 30.8 t ADT: 4,264

SOMERVILLE RD

Poor

Over: I-78 EASTBOUND

2.4 MI EAST OF I-287, Somerset, NJ

Built 1968 Load: 30.8 t ADT: 5,155

SOMERVILLE RD

Poor

Over: I-78 WESTBOUND

2.4 MI EAST OF I-287, Somerset, NJ

Built 1968 Load: 30.8 t ADT: 5,155

MEADOW ROAD

Poor

Over: CHAMBERS BROOK

1.6 mi S of CR 620, Somerset, NJ

Built 2023 Load: 32.4 t ADT: 781

I-78 WESTBOUND

Poor

Over: US 202-206

0.4 MI E OF I-287 JCT, Somerset, NJ

Built 1964 Load: 32.7 t ADT: 56,615

CR 523

Poor

Over: MIDDLE BROOK

0.10 mi S of Large Cross, Somerset, NJ

Built 2001 Load: 32.7 t ADT: 4,905

US 202 & 206 S.B.

Poor

Over: US 22

0.6 MI N OF NJ 28 JCT, Somerset, NJ

Built 1948 Load: 33.6 t ADT: 41,132

READINGTON ROAD

Poor

Over: CHAMBERS BROOK

0.71 mi S of US 22, Somerset, NJ

Built 1930 Load: 33.6 t ADT: 8,509

PRINCE RODGERS AVE

Poor

Over: I-287 NB

2.57 MI NORTH OF US22, Somerset, NJ

Built 1963 Load: 34.5 t ADT: 4,160

PRINCE RODGERS AVE

Poor

Over: I-287 SOUTHBOUND

2.57 mi N of US 22, Somerset, NJ

Built 1963 Load: 34.5 t ADT: 4,160

I-78 EB

Poor

Over: US 202 & 206

.5 MI.E.OF I-78 EXIT-30, Somerset, NJ

Built 1965 Load: 35.4 t ADT: 44,922

I-78 WB

Poor

Over: WASHING VALLEY RD(CR620)

1.1 MI EAST OF I-287 JCT, Somerset, NJ

Built 1965 Load: 37.2 t ADT: 41,583

RAIDER BLVD

Poor

Over: ROYCE BROOK

0.12 MI West of US 206, Somerset, NJ

Built 1981 Load: 41.7 t ADT: 4,599

I-78 WB

Poor

Over: I-287 SB & RAMP G

AT I-287 INTERCHANGE, Somerset, NJ

Built 1963 Load: 42.6 t ADT: 27,489

Picket Pl. (CR567)

Poor

Over: So. Br. of Raritan River

1.4 MI N OF AMWELL RD, Somerset, NJ

Built 1979 Load: 43.5 t ADT: 2,791

ROUTE NJ 28

Poor

Over: CUCKLES BROOK

0.69 MI W OF I-287/28 JCT, Somerset, NJ

Built 1962 Load: 46.3 t ADT: 25,789

NORTH MAPLE AVE.

Poor

Over: I-287 NB

0.19 mi S of US202, Somerset, NJ

Built 1966 Load: 47.2 t ADT: 10,720

NORTH MAPLE AVE.

Poor

Over: I-287 SB

AT I-287 EXIT 30, Somerset, NJ

Built 1966 Load: 47.2 t ADT: 10,934

I-78 EASTBOUND

Poor

Over: I-78 RAMP "A"

0.3 Mi West of I-287 JCT, Somerset, NJ

Built 1963 Load: 49.0 t ADT: 58,865

MOUNTAIN VIEW ROAD

Poor

Over: BEDENS BROOK

0.6 MI SOUTH CR 518, Somerset, NJ

Built 1972 Load: 50.8 t ADT: 340

I-287 NORTHBOUND

Poor

Over: US 202-206

AT I-287 EXIT 22, Somerset, NJ

Built 1965 Load: 55.3 t ADT: 40,484

US202

Poor

Over: N BRANCH RARITAN RIVER

1.03 MI N OF US202-206, Somerset, NJ

Built 1922 Load: 58.1 t ADT: 6,782

READINGTON RD

Poor

Over: TRIB. CHAMBERS BROOK

1.19 MI S. US22, Somerset, NJ

Built 1930 Load: 59.9 t ADT: 8,509

RAMP G OF I-78

Poor

Over: I-287 NB

At I-78 Jct., Somerset, NJ

Built 1964 Load: 68.9 t ADT: 17,707

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

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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.