Total bridges
818
Public highway bridges in Middlesex County
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.
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
- pre-1900 68
Built before 1900
68 bridges
- 1900s 45
1900–1909
45 bridges
- 1910s 21
1910–1919
21 bridges
- 1920s 23
1920–1929
23 bridges
- 1930s 39
1930–1939
39 bridges
- 1940s 25
1940–1949
25 bridges
- 1950s
1950–1959
179 bridges
- 1960s
1960–1969
161 bridges
- 1970s 33
1970–1979
33 bridges
- 1980s 29
1980–1989
29 bridges
- 1990s 45
1990–1999
45 bridges
- 2000s
2000–2009
90 bridges
- 2010s 44
2010–2019
44 bridges
- 2020s 16
2020–2029
16 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).
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.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Worcester County | 1,014 | 25.5% | 66.9% | 7.6% | 1963 |
| Middlesex County (this page) | 818 | 20.7% | 68.2% | 11.1% | 1958 |
| Suffolk County | 489 | 22.7% | 67.7% | 9.6% | 1967 |
| Berkshire County | 450 | 34.7% | 57.6% | 7.8% | 1961 |
| Hampden County | 428 | 17.1% | 75.5% | 7.5% | 1956 |
| Essex County | 395 | 15.9% | 66.8% | 17.2% | 1957 |
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).
- Montgomery County, PA · 828 bridges
- Duval County, FL · 831 bridges
- Davidson County, TN · 832 bridges
- Lancaster County, PA · 801 bridges
Similar average build year
Nearest mean year-built outside MA (1958 here).
- Bucks County, PA · avg 1958 · 699 bridges
- Butte County, CA · avg 1958 · 437 bridges
- Cowley County, KS · avg 1958 · 337 bridges
- Marin County, CA · avg 1958 · 207 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Good-condition bridges (169)
HWY DANFORTH ST
GoodOver: WATER SUDBURY RIVER
.1 MI. E. OF CONCORD ST., Middlesex, MA
Built 1982 Load: 48.6 t ADT: 1,000
HWY BROAD ST
GoodOver: WATER ASSABET RIVER
100 FT S OF WATER ST, Middlesex, MA
Built 2005 Load: 48.6 t ADT: 11,600
I 495 NB/ST 2 CD
GoodOver: ST 2
2 MI.NTH.OF ST.111, Middlesex, MA
Built 2015 Load: 48.6 t ADT: 22,628
ST126 CONCORD ST
GoodOver: ST 9 WORCESTER RD
.5 MI W OF NATICK TL, Middlesex, MA
Built 1931 Load: 48.9 t ADT: 35,500
HWY DEXTER RD
GoodOver: WATER LAUNDRY BROOK
.96 KM. S. OF I-90, Middlesex, MA
Built 1898 Load: 49.0 t ADT: 1,000
ST 2 A/ST110/KING
GoodOver: I 495
1.5 MI N OF RT 2, Middlesex, MA
Built 1960 Load: 49.4 t ADT: 3,845
HWY LOWELL ST
GoodOver: RR MBTA/BMRR
1.8 KM NW OF JCT SR28&38, Middlesex, MA
Built 2006 Load: 49.6 t ADT: 6,077
ST 27 /ST62/WALTHM
GoodOver: WATER ASSABET RIVER
0.1 MI E RT 62, Middlesex, MA
Built 2013 Load: 50.3 t ADT: 12,574
I 95 SB/ST128 SB
GoodOver: ST 38 WB/MAIN ST
RT 128 AT RT 38, Middlesex, MA
Built 1949 Load: 50.4 t ADT: 83,200
ST 62 MAIN ST
GoodOver: WATER ASSABET RIVER
.9 MI EAST OF RT 85, Middlesex, MA
Built 2009 Load: 50.5 t ADT: 7,969
US 3 SB
GoodOver: RR BMRR
1.25 MI NW DRUM HILL, Middlesex, MA
Built 2004 Load: 50.8 t ADT: 50,638
ST 9 /ST30/WRCSTR
GoodOver: WATER SUDBURY RIVER
.25 MI W OF PROSPECT ST, Middlesex, MA
Built 2009 Load: 51.0 t ADT: 52,165
US 3 SB
GoodOver: HWY MAIN ST
2 MI. NW DRUM HILL, Middlesex, MA
Built 2004 Load: 51.1 t ADT: 51,000
HWY SCHOOL ST
GoodOver: COMB KYAN ST & BMRR
0.40 KM S SCHOOL & BRDWAY, Middlesex, MA
Built 1995 Load: 51.2 t ADT: 18,491
ST 16 REV BCH PKWY
GoodOver: WATER MALDEN RIVER
.2 MI W OF SANTILLI CIR, Middlesex, MA
Built 2018 Load: 51.8 t ADT: 68,300
HWY CENTRAL ST
GoodOver: WATER SUDBURY RIVER
.1 MI W OF CONCORD ST, Middlesex, MA
Built 1920 Load: 51.8 t ADT: 8,000
I 495 NB
GoodOver: RR MBTA/BMRR
0.5 MI NE RT 2, Middlesex, MA
Built 1959 Load: 51.8 t ADT: 47,280
HWY CANAL STREET
GoodOver: WATER MERRIMACK CANAL
0.8 KM. W. OF RT. 3A, Middlesex, MA
Built 1986 Load: 52.5 t ADT: 1,250
US 3 NB
GoodOver: HWY WESTFORD RD
1.6 MI S OF ST-113, Middlesex, MA
Built 2004 Load: 53.4 t ADT: 50,100
HWY CATACNEMG RD
GoodOver: WATER CATACUNEMAUG BROOK
.8 M. N. OF LEOMINSTER RD, Middlesex, MA
Built 2002 Load: 54.0 t ADT: 520
HWY CHAPIN RD
GoodOver: WATER ASSABET RIVER
.2 MI S OF RIVER ROAD, Middlesex, MA
Built 1997 Load: 54.2 t ADT: 3,600
ST 27 N MAIN ST
GoodOver: RR MBTA/CSX
0.2 MI. N. OF RT-135, Middlesex, MA
Built 1895 Load: 54.4 t ADT: 23,000
US 3 NB
GoodOver: RR BMRR
1.25 MI NW DRUM HILL, Middlesex, MA
Built 2004 Load: 54.9 t ADT: 49,476
I 495 NB
GoodOver: ST 2
2 MI.NTH.OF ST.111, Middlesex, MA
Built 2015 Load: 55.1 t ADT: 53,214
I 495 SB
GoodOver: ST 2
2MI.NTH.OF ST.111, Middlesex, MA
Built 2015 Load: 55.1 t ADT: 40,908
ST 62 PARK ST
GoodOver: WATER IPSWICH RIVER
0.3 MI E OF HAVERHILL ST, Middlesex, MA
Built 1903 Load: 55.1 t ADT: 9,698
HWY RECREATN RD
GoodOver: I 95 /ST128
0.8 KM S MASS PIKE, Middlesex, MA
Built 2009 Load: 55.1 t ADT: 7,760
ST128 SERVICE RD
GoodOver: WATER CHARLES RIVER
NEWTON-WESTON TOWN LINE, Middlesex, MA
Built 1949 Load: 55.4 t ADT: 43,300
HWY FOUNTAIN ST
GoodOver: RR MBTA/CSX
.1 MI. N. OF ST-135, Middlesex, MA
Built 2001 Load: 56.1 t ADT: 4,500
US 3 SB
GoodOver: ST 62 BURLINGTON RD
RT 3 AT RT 62, Middlesex, MA
Built 2004 Load: 56.3 t ADT: 38,322
US 3 NB
GoodOver: WATER CONCORD RIVER
0.5 MI NW RT3 & CNCRD RD, Middlesex, MA
Built 2004 Load: 56.8 t ADT: 81,500
US 3 SB
GoodOver: WATER CONCORD RIVER
0.5 MI NW RT3 & CNCRD RD, Middlesex, MA
Built 2004 Load: 56.8 t ADT: 86,400
ST 4 NB
GoodOver: US 3 NB/SB
2.2 MI N OF I 495, Middlesex, MA
Built 2004 Load: 56.8 t ADT: 14,416
US 3 NB
GoodOver: ST 62 BURLINGTON RD
RT 3 AT RT 62, Middlesex, MA
Built 2004 Load: 56.9 t ADT: 51,663
US 3 NB
GoodOver: WATER SHAWSHEEN RIVER
0.5 MI NW RT 62 & RT 3, Middlesex, MA
Built 2004 Load: 57.5 t ADT: 60,000
US 3 SB
GoodOver: WATER SHAWSHEEN RIVER
0.5 MI NW RT 62 & RT 3, Middlesex, MA
Built 2004 Load: 57.5 t ADT: 60,000
ST 4 NASHUA RD
GoodOver: WATER CONCORD RIVER
1 MI N OF BEDFORD T.L., Middlesex, MA
Built 2008 Load: 58.0 t ADT: 13,600
ST 3 NB
GoodOver: US 3 SB CONNECTOR
0.25 M SLY N.H. LINE, Middlesex, MA
Built 2004 Load: 58.2 t ADT: 48,000
ST 3 SB
GoodOver: US 3 SB CONNECTOR
0.25 MI SLY NH LINE, Middlesex, MA
Built 2004 Load: 58.5 t ADT: 42,200
US 3 SB
GoodOver: HWY WESTFORD RD
1.6 MI S OF ST-113, Middlesex, MA
Built 2004 Load: 58.7 t ADT: 60,000
US 3 NB
GoodOver: HWY RICHARDSON RD
0.75 MI NW DRUM HILL, Middlesex, MA
Built 2004 Load: 59.5 t ADT: 49,476
ST 2 A/MASS AVE
GoodOver: ST 3 MEMORIAL DR
N END HARVARD BR, Middlesex, MA
Built 1931 Load: 59.7 t ADT: 20,560
US 3 NB
GoodOver: HWY DUNSTABLE RD
1.5 MI. N OF RTE 40, Middlesex, MA
Built 2004 Load: 60.4 t ADT: 82,679
US 3 SB
GoodOver: HWY DUNSTABLE RD
1.5 MI. N. OF RTE 40, Middlesex, MA
Built 2004 Load: 60.4 t ADT: 77,900
HWY CANAL ST
GoodOver: WATER HAMILTON CANAL
@ JACKSON & REVERE ST INT, Middlesex, MA
Built 2012 Load: 61.6 t ADT: 1,000
HWY WINTER ST
GoodOver: RR MBTA/CSX
.1MI.NTH.OF ST.135, Middlesex, MA
Built 2017 Load: 64.8 t ADT: 13,248
HWY NB LOWLL CON
GoodOver: HWY PLAIN ST
1.2 MILES N. OF I495, Middlesex, MA
Built 2012 Load: 66.9 t ADT: 23,194
HWY SB LOWLL CON
GoodOver: HWY PLAIN ST
1.2 MILES N OF I-495, Middlesex, MA
Built 2012 Load: 66.9 t ADT: 23,300
HWY WHITNEY ST
GoodOver: RR CSX
1.5 MI. NTH OF ST-16, Middlesex, MA
Built 2008 Load: 67.0 t ADT: 5,700
HWY MORTON ST
GoodOver: RR BMRR
0.16 KM E LAWRENCE STREET, Middlesex, MA
Built 2010 Load: 67.6 t ADT: 130
Read our methodology - how this data is sourced, computed, and verified.
Related
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.