County profile · official public datasets

Middlesex County, NJ

563 public highway bridges tracked in the FHWA National Bridge Inventory: 23.4% rated Good, 72.1% Fair, 4.4% Poor.

563
Public bridges
23.4%
Good condition
4.4%
Poor condition

The verdict

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

Middlesex County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 33%
lowest Poor share in state
4.4%
Poor-condition share
563
public highway bridges
1972
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.

Middlesex County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Middlesex County ranks #7 of 21 New Jersey counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.4%). Middlesex County, New Jersey contains 563 public highway bridges. Roughly 23.4% are rated “Good,” 72.1% “Fair,” and 4.4% “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

563

Public highway bridges in Middlesex County

Good condition

23.4%

132 of 563 rated 7-9

Fair condition

72.1%

406 of 563 rated 5-6

Poor condition

4.4%

25 of 563 rated 4 or below

In-state Poor-share rank

#7 of 21

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

Condition distribution

Share of 563 NBI-tracked bridges by lowest applicable component rating.

Good
23.4% (132)
Fair
72.1% (406)
Poor
4.4% (25)

Middlesex County's Poor-condition bridges carry 402,662 vehicle crossings a day

That is 2.1% of the county's reported daily bridge traffic on 4.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 16,106 crossings a day against 29,014 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 563 of 563 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

58.6% of Middlesex County's bridges have passed the 50-year mark

330 of the 563 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 23.4% 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 16.8% of the county's Poor-condition bridge traffic

US 1 over FORRESTAL ROAD, built 1932, carries 67,565 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 25-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 402,662 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Middlesex County's bridges were built

563 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1970s, when 125 of the county's bridges still in the inventory were built, which is 22.2% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1972, 6 years newer than the New Jersey average of 1966.

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

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

The 5 New Jersey counties nearest Middlesex County in number of bridges, with their condition splits. Its 4.4% Poor share is the 2nd-lowest of these 6. Its average build year of 1972 against a peer-group mean of 1967 is 5 years newer.

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

Bridge inventory size and condition shares for Middlesex County and the 5 New Jersey counties closest to it in inventory size
County Bridges Poor
Bergen County 577 4.9%
Middlesex County (this page) 563 4.4%
Morris County 508 5.9%
Essex County 505 2.8%
Monmouth County 505 8.9%
Mercer County 414 9.2%

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 Middlesex 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 Middlesex County, both outside New Jersey so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside NJ (563 bridges here).

Similar average build year

Nearest mean year-built outside NJ (1972 here).

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

All 563 Good 132 Fair 406 Poor 25

All bridges (563)

MIDDLESEX CEN BLVD

Fair

Over: STREAM

0.19 mi S. Davidsons Mill, Middlesex, NJ

Built 2005 Load: 99.9 t ADT: 139

US 1 to CR522 Ramp

Fair

Over: Tributary to Heathcote

500 East of US Route 1, Middlesex, NJ

Built 2013 Load: 99.9 t ADT: 1,183

TPK NSI/SNI/SNO

Fair

Over: Ireland Brook

0.4mi. S. of CR 694, Middlesex, NJ

Built 1951 Load: 99.9 t ADT: 91,953

NJTP SNI-NSI RWYS

Fair

Over: SAW MILL BROOK

1.4 MI S INTERCHANGE 9, Middlesex, NJ

Built 1950 Load: 99.9 t ADT: 66,647

NJ TURNPIKE(I-95)

Fair

Over: MILL BROOK

1.4 MI S INTERCHANGE 10, Middlesex, NJ

Built 1950 Load: 99.9 t ADT: 175,389

NJ TURNPIKE(I-95)

Fair

Over: MILL BROOK

3 MI N OF Exit 9/ Rt. 18, Middlesex, NJ

Built 1950 Load: 99.9 t ADT: 175,376

US RT 9

Good

Over: MAIN STREET

0.8 MI SOUTH OF RT 1 JCT., Middlesex, NJ

Built 1937 Load: 24.3 t ADT: 82,456

US 130 NB

Good

Over: US 1 + Connectors

Over Route US 1 NB/SB, Middlesex, NJ

Built 2003 Load: 24.6 t ADT: 35,495

NJTPK Ramps ET1&WT

Good

Over: Ramps TE2 & ET2

.1 Mi E of Int. 12, Middlesex, NJ

Built 2009 Load: 24.6 t ADT: 3,800

US 9 SOUTHBOUND

Good

Over: US 9 RAMP GM

0.25 MI NORTH OF RT440, Middlesex, NJ

Built 1972 Load: 25.3 t ADT: 47,042

Ryders Lane(CR617)

Good

Over: SAWMILL BROOK

1 MI S OF US 1, Middlesex, NJ

Built 2009 Load: 26.3 t ADT: 26,548

Ramp SASI

Good

Over: NJTPK (I-95)

Service Are to Inner Rd, Middlesex, NJ

Built 2013 Load: 26.9 t ADT: 6,229

NJ TPK SNO ROADWAY

Good

Over: WESTONS MILL POND

2.5 MI SOUTH OF INT 9, Middlesex, NJ

Built 1990 Load: 27.9 t ADT: 46,023

NJ TPK NSO ROADWAY

Good

Over: WESTONS MILL POND

2.5 MI SOUTH OF INT 9, Middlesex, NJ

Built 1990 Load: 27.9 t ADT: 46,023

CR 656 (SMITH ST)

Good

Over: RAMP FOR US 9 & NJ 440

0.20 MI EAST OF US9, Middlesex, NJ

Built 1972 Load: 28.1 t ADT: 25,966

NJ TPK NSO ROADWAY

Good

Over: SHALLOW BROOK (WETLANDS)

0.77 MI S OF EXIT 8A, Middlesex, NJ

Built 1990 Load: 29.5 t ADT: 39,678

US 9 SB

Good

Over: Raritan Riv CR656 RampR

1.08 MI. S OF NJ 440, Middlesex, NJ

Built 2002 Load: 30.8 t ADT: 40,340

GREEN ST. (CR 604)

Good

Over: TRIB TO RAHWAY RIVER

AT INT. CHAIN-O-HILLS RD., Middlesex, NJ

Built 1984 Load: 30.8 t ADT: 14,342

I-287 NB

Good

Over: NJ 18 SP.(POSSUMTOWN RD)

1.77 MI E OF RARITAN RIV, Middlesex, NJ

Built 1962 Load: 31.4 t ADT: 63,197

GSP SB

Good

Over: RARITAN RIVER SMITH ST.

0.5 MI SOUTH OF ROUTE 440, Middlesex, NJ

Built 2006 Load: 31.4 t ADT: 109,273

US RT 9 NB

Good

Over: RARITAN RIVER SMITH ST.

1.1 MI. S OF NJ 440, Middlesex, NJ

Built 2003 Load: 31.8 t ADT: 46,321

COMMERCIAL AVENUE

Good

Over: ROUTE NJ 18

1.14 miles northof Rt.1&R, Middlesex, NJ

Built 2008 Load: 32.4 t ADT: 2,283

WEDGEWOOD AVENUE

Good

Over: WEDGEWOOD BROOK

0.02 mile west of CR 514, Middlesex, NJ

Built 2007 Load: 32.7 t ADT: 823

RAHWAY AVE(RT 514)

Good

Over: WEDGEWOOD BROOK

1.0 MI NORTH OF RT 35 JCT, Middlesex, NJ

Built 1976 Load: 32.7 t ADT: 13,268

PROLOGIS WAY(CR643

Good

Over: TRIBUTARY OF ARTHUR KILL

0.81 miles east of CR 604, Middlesex, NJ

Built 2008 Load: 32.7 t ADT: 597

PROLOGIS WAY CR643

Good

Over: TRIBUTARY OF ARTHUR KILL

1.07 miles east of CR 604, Middlesex, NJ

Built 2008 Load: 32.7 t ADT: 594

HAWTHORNE AVE

Good

Over: PUMPKIN PATCH BROOK

0.5M S OF INMAN AVE, Middlesex, NJ

Built 1971 Load: 32.7 t ADT: 369

BELMONT AVENUE

Good

Over: BOUND BROOK

3.8 MILES S OF ROUTE 28, Middlesex, NJ

Built 1965 Load: 32.7 t ADT: 2,986

MILLBROOK COURT

Good

Over: SAWMILL BROOK

0.6 miles North of CR606, Middlesex, NJ

Built 1998 Load: 32.7 t ADT: 8

AARON ROAD

Good

Over: TRIB. OF SIX MILE RUN

0.43 miles north of US 1, Middlesex, NJ

Built 1970 Load: 32.7 t ADT: 1,801

APPLEGARTH ROAD

Good

Over: MILLSTONE RIVER

0.49 MI NORTH OF NJ 33, Middlesex, NJ

Built 1995 Load: 32.7 t ADT: 11,333

TPKNSO/NSI/SNI/SNO

Good

Over: Colonial Pipelines

1.83 Mi. South of Int. 12, Middlesex, NJ

Built 1947 Load: 32.7 t ADT: 196,710

NJTPK(I-95)NSO RWY

Good

Over: LAWRENCE BROOK

.1 MI N INTERCHANGE 9, Middlesex, NJ

Built 1973 Load: 33.0 t ADT: 56,697

NJ 28(BOUND BK RD)

Good

Over: BONYGUTT BROOK

0.73 MI WEST OF CR 529, Middlesex, NJ

Built 1979 Load: 33.6 t ADT: 12,269

ENGLISHTOWN RD

Good

Over: BARCLAYS BROOK

2.5 MI SW JCT RTES 9 & 18, Middlesex, NJ

Built 1996 Load: 33.6 t ADT: 12,041

Aster Circle

Good

Over: Trib. Tennents Brook

1.0 mil. W of NJ RT 9, Middlesex, NJ

Built 2013 Load: 34.5 t ADT: 102

Ramp NISA

Good

Over: NJTPK (I-95)

Molly Pitcher Serv. Area, Middlesex, NJ

Built 2014 Load: 34.7 t ADT: 6,229

NJTPK Ramp SSP&SPN

Good

Over: NJTPK(I-95)

3 MI N RTE 33 & NJ TPK, Middlesex, NJ

Built 2011 Load: 35.0 t ADT: 126

PROSPECT AVENUE

Good

Over: BOUND BROOK

1 MI. EAST OF ST. HWY. 28, Middlesex, NJ

Built 2003 Load: 35.4 t ADT: 4,893

Prospect Plains Rd

Good

Over: NJ TPK

3.8 MI N RTE 33 & NJ TPK, Middlesex, NJ

Built 2012 Load: 36.0 t ADT: 12,076

SCUDDERS MILL ROAD

Good

Over: US 1

1.2 MI NORTH OF CO RT 571, Middlesex, NJ

Built 1995 Load: 36.3 t ADT: 7,777

NJ 18

Good

Over: S.RIVER CONRAIL MAIN ST

0.4 MI N OF CR 516, Middlesex, NJ

Built 1999 Load: 36.3 t ADT: 57,073

BAEKELAND AVENUE

Good

Over: AMBROSE BROOK

0.07 miles W of Cedar Ave, Middlesex, NJ

Built 2019 Load: 36.3 t ADT: 9,139

NSO ROADWAY

Good

Over: HIGHTSTOWN-CRANBURY ROAD

2.1 MI NORTH OF EXIT 8, Middlesex, NJ

Built 2013 Load: 37.3 t ADT: 40,107

Ramp TSI

Good

Over: NSO Roadway

0.4 MI N OF NJ32&NJTPK, Middlesex, NJ

Built 2012 Load: 37.6 t ADT: 10,510

DANIEL ROAD

Good

Over: MANALAPAN BROOK

0.13 MILE SOUTH OF CR 615, Middlesex, NJ

Built 2001 Load: 38.1 t ADT: 1,566

DUTCH ROAD

Good

Over: NJ TPK NSO-NSI-SNI-SNO

3.5 MI SOUTH OF INT 9, Middlesex, NJ

Built 1990 Load: 38.6 t ADT: 2,395

SNO ROADWAY

Good

Over: HIGHTSTOWN-CRANBURY ROAD

2.1 MI NORTH OF EXIT 8, Middlesex, NJ

Built 2013 Load: 38.9 t ADT: 40,107

PROLOGIS WAY CR643

Good

Over: TRIBUTARY OF ARTHUR KILL

0.05 miles east of CR 604, Middlesex, NJ

Built 2008 Load: 39.0 t ADT: 597

NJTPKRampsWT ET&TE

Good

Over: Creek (Culvert)

.7 Mi. E. of Int. 12, Middlesex, NJ

Built 2004 Load: 39.2 t ADT: 3,750

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

Related

Browse all → | Rankings →
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.