County profile · official public datasets

Middlesex County, MA

818 public highway bridges tracked in the FHWA National Bridge Inventory: 20.7% rated Good, 68.2% Fair, 11.1% Poor.

818
Public bridges
20.7%
Good condition
11.1%
Poor condition

The verdict

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

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

11th
of 13 on Poor share
11.1%
Poor-condition share
818
public highway bridges
1958
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 #11 of 13 Massachusetts counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 11.1%). Middlesex County, Massachusetts contains 818 public highway bridges. Roughly 20.7% are rated “Good,” 68.2% “Fair,” and 11.1% “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

818

Public highway bridges in Middlesex County

Good condition

20.7%

169 of 818 rated 7-9

Fair condition

68.2%

558 of 818 rated 5-6

Poor condition

11.1%

91 of 818 rated 4 or below

In-state Poor-share rank

#11 of 13

Among Massachusetts counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 818 NBI-tracked bridges by lowest applicable component rating.

Good
20.7% (169)
Fair
68.2% (558)
Poor
11.1% (91)

Middlesex County's Poor-condition bridges carry 3,395,813 vehicle crossings a day

That is 12.7% of the county's reported daily bridge traffic on 11.1% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 37,317 crossings a day against 21,585 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 818 of 818 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

70.5% of Middlesex County's bridges have passed the 50-year mark

577 of the 818 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 20.7% 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 5.9% of the county's Poor-condition bridge traffic

I 93 over I 95 /ST128, built 1957, carries 200,824 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 91-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 3,395,813 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

818 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1950s, when 179 of the county's bridges still in the inventory were built, which is 21.9% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year (1958) matches the Massachusetts average (1961).

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

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

The 5 Massachusetts counties nearest Middlesex County in number of bridges, with their condition splits. Its 11.1% Poor share is the 5th-lowest of these 6. Its average build year of 1958 against a peer-group mean of 1961 is in line with the group.

Showing the 5 closest of 12 Massachusetts counties eligible for comparison.

Bridge inventory size and condition shares for Middlesex County and the 5 Massachusetts counties closest to it in inventory size
County Bridges Poor
Worcester County 1,014 7.6%
Middlesex County (this page) 818 11.1%
Suffolk County 489 9.6%
Berkshire County 450 7.8%
Hampden County 428 7.5%
Essex County 395 17.2%

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 Massachusetts so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside MA (818 bridges here).

Similar average build year

Nearest mean year-built outside MA (1958 here).

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

All 818 Good 169 Fair 558 Poor 91

Good-condition bridges (169)

HWY WETHERBEE ST

Good

Over: WATER NASHOBA BROOK

500 FT S OF RT 2A, Middlesex, MA

Built 1997 Load: 35.7 t ADT: 2,586

HWY NICHOLS ST

Good

Over: RR MBTA/BMRR

.32 KM SW TEWKSBURY, Middlesex, MA

Built 1968 Load: 35.7 t ADT: 3,400

HWY VINTON PD RD

Good

Over: WATER PEARL HILL BROOK

.1 MI W FITCHBURG RD, Middlesex, MA

Built 2009 Load: 35.8 t ADT: 200

HWY BOYLSTON ST

Good

Over: RR BMRR

0.4 KM N RTE 495, Middlesex, MA

Built 1999 Load: 35.9 t ADT: 17,500

HWY COOPER ST

Good

Over: RR MBTA/BMRR

JUST OFF MYRTLE AVE, Middlesex, MA

Built 1919 Load: 36.0 t ADT: 2,069

HWY PHINEAS ST

Good

Over: WATER BEAVER BROOK

3.4 MI N OF RT 3, Middlesex, MA

Built 1995 Load: 36.2 t ADT: 6,100

I 495

Good

Over: WATER MILL POND

@MM 78.7 1.25 MI NE RT 2, Middlesex, MA

Built 1961 Load: 36.5 t ADT: 107,705

HWY EAMES ST

Good

Over: RR MBTA/BMRR

0.4 MI NE OF RTE 38, Middlesex, MA

Built 1994 Load: 36.7 t ADT: 5,800

HWY BOUNDARY ST

Good

Over: WATER ASSABET RIVER

100 FT. SE OF NTHBRO T.L., Middlesex, MA

Built 2010 Load: 36.9 t ADT: 4,239

ST119 SOUTH RD

Good

Over: WATER NASHUA RIVER

AT PEPPERELL TOWN LINE, Middlesex, MA

Built 1931 Load: 37.7 t ADT: 13,298

HWY WILEY ST

Good

Over: WATER MILL RIVER

.16 KM. S. OF RT. 129, Middlesex, MA

Built 1971 Load: 38.8 t ADT: 500

HWY MAIN ST

Good

Over: WATER SALMON BROOK

.5 MI. N. OF RTE 113, Middlesex, MA

Built 2014 Load: 38.9 t ADT: 2,600

ST 85 RIVER ST

Good

Over: WATER SUDBURY RIVER

1000FT S.OF SOUTHVILLE RD, Middlesex, MA

Built 2014 Load: 38.9 t ADT: 8,359

ST 2

Good

Over: I 95 /ST128

1.6 KM S RT 2A & RT 128, Middlesex, MA

Built 2016 Load: 38.9 t ADT: 84,703

HWY MILL ST

Good

Over: WATER SHAWSHEEN RIVER

1 MI. N. OF RT. 38, Middlesex, MA

Built 1998 Load: 38.9 t ADT: 170

HWY ACCESS RD

Good

Over: WATER STONY BROOK

AT WESTON TRANSFER STA, Middlesex, MA

Built 2013 Load: 38.9 t ADT: 1,034

HWY UNIVRSTY AVE

Good

Over: WATER MERRIMACK & CANAL

0.2 MI S OF RTE 113, Middlesex, MA

Built 2014 Load: 39.3 t ADT: 13,500

HWY ROBIN HLL ST

Good

Over: WATER ASSABET RIVER

.2 MI NE OF NORTHBORO TL, Middlesex, MA

Built 2010 Load: 39.8 t ADT: 1,300

I 495 NB

Good

Over: WATER CONCORD RIVER

3.2KM SOUTH OF RT 38, Middlesex, MA

Built 2011 Load: 40.6 t ADT: 61,200

I 495 NB

Good

Over: HWY WOBURN ST

AT JCT I495 & WOBURN ST., Middlesex, MA

Built 2011 Load: 40.6 t ADT: 64,233

I 290

Good

Over: WATER ASSABET RIVER

MM30.8 E OF SLMN PD RD, Middlesex, MA

Built 1968 Load: 40.7 t ADT: 75,828

HWY LANDHAM RD

Good

Over: WATER HOP BROOK

.3 MI S OF RTE 20, Middlesex, MA

Built 2013 Load: 40.7 t ADT: 17,720

HWY WALDEN ST

Good

Over: RR MBTA/BMRR

2.1 KM S OF JCT SR2A&16, Middlesex, MA

Built 2009 Load: 41.1 t ADT: 9,181

US 3 /ST2&16/ALWF

Good

Over: RR MBTA/BMRR

.1 MI S OF RINGE AVE, Middlesex, MA

Built 1996 Load: 41.8 t ADT: 77,800

I 495 SB

Good

Over: HWY WOBURN ST

AT I495 & WOBURN ST., Middlesex, MA

Built 2011 Load: 41.8 t ADT: 64,355

ST 85 WASHNGTON ST

Good

Over: WATER ASSABET RIVER

0.25 MI SOUTH OF ST 62, Middlesex, MA

Built 2017 Load: 42.1 t ADT: 8,394

HWY MILL ST

Good

Over: WATER NISSITISSIT RIVER

.2 MI NORTH OF ST-113, Middlesex, MA

Built 2012 Load: 42.1 t ADT: 7,500

ST 28 MCGRATH HWY

Good

Over: HWY GILMAN ST

.1 MI S OF EVERETT AVE, Middlesex, MA

Built 2016 Load: 42.1 t ADT: 45,425

HWY LUNDBERG ST

Good

Over: RR MBTA/BMRR

0.25 MI NE RT 3A & LNDBRG, Middlesex, MA

Built 1922 Load: 42.3 t ADT: 2,750

ST 38 MAIN ST

Good

Over: WATER SHAWSHEEN RIVER

.24 KM SELY SHAWSHEEN ST., Middlesex, MA

Built 1997 Load: 42.5 t ADT: 21,500

I 495 SB

Good

Over: RR MBTA/BMRR

50 FT S OF WOBURN ST EXIT, Middlesex, MA

Built 2011 Load: 42.7 t ADT: 64,100

HWY SHAKER RD

Good

Over: WATER CATACUNEMAUG BROOK

@ INT. FREDONIAN ST., Middlesex, MA

Built 2011 Load: 42.7 t ADT: 600

I 495 NB

Good

Over: RR MBTA/BMRR

50 FT S OF WOBURN ST EXIT, Middlesex, MA

Built 2011 Load: 43.3 t ADT: 61,500

ST129 LOWELL ST

Good

Over: WATER MAPLE MEADOW BROOK

0.85 KM E OF JCT ST38, Middlesex, MA

Built 2008 Load: 43.4 t ADT: 28,600

HWY UNION AVE

Good

Over: WATER SUDBURY RIVER

.4 MI S OF MAIN ST, Middlesex, MA

Built 1985 Load: 43.5 t ADT: 14,143

HWY MINERAL ST

Good

Over: RR MBTA/BMRR

0.32 KM NE SUMMER AVE, Middlesex, MA

Built 1997 Load: 43.7 t ADT: 4,100

HWY TAYLOR ST

Good

Over: ST 2

.2 MI WEST OF I-495, Middlesex, MA

Built 2006 Load: 44.2 t ADT: 5,036

I 495 SB

Good

Over: WATER CONCORD RIVER

3.2KM SOUTH OF RT 38, Middlesex, MA

Built 2011 Load: 44.7 t ADT: 64,400

HWY PARKER ST

Good

Over: WATER FORT POND BROOK

CORNER OF CLOVER HILL RD, Middlesex, MA

Built 2018 Load: 45.4 t ADT: 3,000

HWY MEADOWBRK RD

Good

Over: WATER CANAL

.16 KM S OF RT 3, Middlesex, MA

Built 1950 Load: 45.4 t ADT: 1,300

I 495 SB

Good

Over: RR MBTA/BMRR

0.5 MI N OF RT 2, Middlesex, MA

Built 1959 Load: 45.4 t ADT: 43,698

HWY MARION ST

Good

Over: RR MBTA/CSX

0.3 MI N RT 135, Middlesex, MA

Built 1896 Load: 45.4 t ADT: 2,703

ST 9 WORCESTER ST

Good

Over: WATER LAKE COCHITUATE

0.6 MI W OF JCT RTE 9 &27, Middlesex, MA

Built 2007 Load: 45.7 t ADT: 52,165

HWY COCHTUATE ST

Good

Over: OTHER COCHITUATE RAIL TR

0.2 MI.WST.OF ST.27, Middlesex, MA

Built 1896 Load: 45.9 t ADT: 1,300

US 20 BOSTN PST RD

Good

Over: WATER SUDBURY RIVER

.75 MI. W. OF ST-27, Middlesex, MA

Built 2009 Load: 46.5 t ADT: 15,800

ST 2

Good

Over: TR MNUTEMAN BP

JUST W OLD ALEWIFE ROTARY, Middlesex, MA

Built 2004 Load: 47.4 t ADT: 70,300

HWY WHEELER RD

Good

Over: WATER WILLARD BROOK

AT CORNER OF RT.119, Middlesex, MA

Built 2011 Load: 47.4 t ADT: 2,597

HWY HERBERT ST

Good

Over: WATER BEAVER DAM BROOK

AT CORNER OF TRIPP ST., Middlesex, MA

Built 2009 Load: 47.5 t ADT: 8,300

HWY PAGE RD

Good

Over: WATER SHAWSHEEN RIVER

.1MI E OF RT 62, Middlesex, MA

Built 2009 Load: 48.0 t ADT: 9,900

HWY MERIAM ST

Good

Over: RR MBTA/BMRR

JUST OFF MAIN ST, Middlesex, MA

Built 2001 Load: 48.0 t ADT: 1,422

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.