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.
Fair-condition bridges (558)
I 93
FairOver: ST 28 & ST38 & TEMPLE ST
3.2 KM N OF JCT I-93&US-1, Middlesex, MA
Built 1973 Load: 0.0 t ADT: 143,941
ST 62 GLEASNDLE RD
FairOver: WATER ASSABET RIVER
0.4 MI N OF HUDSON TL, Middlesex, MA
Built 1947 Load: 0.0 t ADT: 4,695
HWY BUTTERS ROW
FairOver: RR MBTA/BMRR
0.1 MI W RT 38, Middlesex, MA
Built 1920 Load: 8.1 t ADT: 1,950
HWY COMMNWLTH AV
FairOver: WATER FORT POND BROOK
.2 MI NW OF RTE 62, Middlesex, MA
Built 1909 Load: 9.0 t ADT: 10,381
HWY MERRIAM ST
FairOver: RR MBTA/BMRR
0.48 KM S RT 117, Middlesex, MA
Built 1928 Load: 9.5 t ADT: 2,716
HWY BROOKS CROSS
FairOver: WATER MASON BROOK
1500 FT S OF NH S.L., Middlesex, MA
Built 1986 Load: 11.0 t ADT: 120
HWY WHEELER RD
FairOver: WATER ELIZABETH BROOK
.5 MILES SOUTH OF ST -117, Middlesex, MA
Built 1969 Load: 12.2 t ADT: 800
HWY JACKSON ST
FairOver: RR MBTA/BMRR
0.16 KM S CENTRAL ST, Middlesex, MA
Built 1934 Load: 12.3 t ADT: 2,100
US 3 MEMORIAL DR
FairOver: RR CSX
.32 KM E OF MAGAZINE ST, Middlesex, MA
Built 1906 Load: 13.3 t ADT: 41,897
ST119 MAIN ST
FairOver: WATER SQUANNACOOK RIVER
0.2 MI WLY RT 13, Middlesex, MA
Built 1950 Load: 16.5 t ADT: 10,140
HWY PARKER AVE
FairOver: WATER BEAVER BROOK
.3 MI NE OF MAMMOTH RD, Middlesex, MA
Built 1956 Load: 17.1 t ADT: 6,000
HWY MARKET ST
FairOver: WATER MERRIMACK CANAL
AT INTER WITH DUTTON ST, Middlesex, MA
Built 1912 Load: 17.8 t ADT: 6,500
I 93 SB ON RAMP
FairOver: OTHER TRI COMMUNITY GREE
0.1 MI S MONTVALE AVE, Middlesex, MA
Built 1958 Load: 18.0 t ADT: 6,100
HWY FRUIT ST
FairOver: I 495
.2 MI. S.OF I-90, Middlesex, MA
Built 1966 Load: 19.0 t ADT: 3,916
I 95 /ST128
FairOver: WATER CHARLES RIVER
NEWTON-WELLESLEY TWN LINE, Middlesex, MA
Built 1950 Load: 19.0 t ADT: 142,579
HWY COX ST
FairOver: WATER ASSABET RIVER
.5 MI NW OF RTE 62, Middlesex, MA
Built 1928 Load: 19.3 t ADT: 8,300
HWY BRIDGE ST
FairOver: WATER MERRIMACK RIVER
0.25 MI W FALLS & RT 110, Middlesex, MA
Built 1937 Load: 19.4 t ADT: 19,564
HWY FRENCH ST
FairOver: WATER MERRIMACK CANAL
AT HIGH SCHOOL, Middlesex, MA
Built 1960 Load: 19.4 t ADT: 99,300
HWY WINTER ST
FairOver: I 90
0.8 MI E OF NATICK TWN LN, Middlesex, MA
Built 1957 Load: 19.6 t ADT: 1,700
HWY LINCOLN ST
FairOver: WATER RIVER MEADOW BROOK
0.25 MI N CONNCTR & PLAIN, Middlesex, MA
Built 1960 Load: 19.9 t ADT: 7,900
ST111 HOLLIS ST
FairOver: WATER NISSITISSIT RIVER
200 FT S OF NASHUA RD, Middlesex, MA
Built 1958 Load: 20.1 t ADT: 9,300
ST 2 ELM ST
FairOver: WATER ASSABET RIVER
0.64 KM E RT 2 ROTARY, Middlesex, MA
Built 1904 Load: 20.2 t ADT: 47,800
HWY MEMORL DR EB
FairOver: WATER CHARLES RIVER
JUST S OF LONGFELLOW BR, Middlesex, MA
Built 1956 Load: 20.8 t ADT: 13,000
I 495 NB
FairOver: HWY DONALD LYNCH BLVD
.1 MI N OF I-290, Middlesex, MA
Built 1963 Load: 21.0 t ADT: 48,156
US 3 /ST2&16/ALWF
FairOver: HWY ALW STA ACCESS RD
.32 KM N OF RINGE AVE, Middlesex, MA
Built 1984 Load: 21.2 t ADT: 54,568
HWY GROVE ST
FairOver: I 90
I-90 MM 113.5, Middlesex, MA
Built 1957 Load: 21.2 t ADT: 3,690
HWY SHORE RD
FairOver: WATER ABERJONA RIVER
45 M W. OF SKILLING RD, Middlesex, MA
Built 1955 Load: 22.4 t ADT: 646
ST 9 BOYLSTON ST
FairOver: HWY CENTRE ST
1.5 MI ELY RT 128, Middlesex, MA
Built 1932 Load: 22.5 t ADT: 73,966
I 95 /ST128
FairOver: HWY NORUMBEGA RD
0.2 MI NLY RT 30, Middlesex, MA
Built 1950 Load: 22.6 t ADT: 147,364
ST 4 GREAT RD
FairOver: WATER SHAWSHEEN RIVER
1.25 MI NW RT 128 & BDFRD, Middlesex, MA
Built 1903 Load: 22.7 t ADT: 37,000
HWY MT WAYTE AVE
FairOver: RR CSX
.7 MI. N. OF ST-135, Middlesex, MA
Built 1947 Load: 22.7 t ADT: 10,000
ST 3 A/BOSTON RD
FairOver: WATER SHAWSHEEN RIVER
0.25 MI E RT3A/ALLEN RD, Middlesex, MA
Built 1915 Load: 22.9 t ADT: 19,400
HWY WALES ST
FairOver: WATER CHARLES RIVER
@ WELLESLEY TL = W13002, Middlesex, MA
Built 1928 Load: 22.9 t ADT: 25,086
HWY SPRING ST
FairOver: ST 2
0.5 MI E OF ST-128, Middlesex, MA
Built 1967 Load: 23.0 t ADT: 12,434
I 90 RAMP G
FairOver: I 90 & RAMP K
AT INT 15 S3, Middlesex, MA
Built 1962 Load: 23.2 t ADT: 24,569
HWY WINTER ST
FairOver: WATER SUDBURY RIVER
.6 M S OF RTE 9, Middlesex, MA
Built 1877 Load: 23.3 t ADT: 14,300
I 95 /ST128
FairOver: RR MBTA/BMRR
1.2 MI NELY RT 28, Middlesex, MA
Built 1950 Load: 23.3 t ADT: 144,478
HWY TRAPELO RD
FairOver: RR MBTA/BMRR
WAVERLY SQ NEAR ST 60, Middlesex, MA
Built 1952 Load: 23.6 t ADT: 14,900
HWY NB LOWLL CON
FairOver: HWY INDSTRIAL AVE EAST
0.3 MI N OF I-495, Middlesex, MA
Built 1960 Load: 23.6 t ADT: 35,000
ST225 BEDFORD RD
FairOver: WATER CONCORD RIVER
AT TWNLN BEDFORD-CARLISLE, Middlesex, MA
Built 1955 Load: 23.7 t ADT: 9,750
ST 27 OLD SUDBURY
FairOver: WATER SUDBURY RIVER
AT RIVER RD, Middlesex, MA
Built 1956 Load: 23.9 t ADT: 12,500
I 95 SB/ST128 SB
FairOver: HWY WINN ST
0.75 MI NE RT 95 & RT 3A, Middlesex, MA
Built 1949 Load: 24.0 t ADT: 99,185
HWY LANDHAM RD
FairOver: RR BMRR (ABANDONED)
300 FT S OF RT. 20, Middlesex, MA
Built 1970 Load: 24.2 t ADT: 13,356
HWY FARWELL ST
FairOver: WATER CHARLES RIVER
AT CHARLES RIVER, Middlesex, MA
Built 1850 Load: 24.2 t ADT: 20,252
ST117 GREAT RD
FairOver: WATER ELIZABETH BROOK
100 FT. EAST OF HUDSON RD, Middlesex, MA
Built 1952 Load: 24.3 t ADT: 12,844
HWY PARKER ST
FairOver: ST 9 BOYLSTON ST
2.1 MI. EAST RTE. 128, Middlesex, MA
Built 1932 Load: 24.4 t ADT: 20,302
HWY OAK ST
FairOver: I 90
AT I-90 MM 110.2, Middlesex, MA
Built 1957 Load: 24.5 t ADT: 2,200
I 95 /ST128
FairOver: ST129 WB MAIN ST
RT 128 AT RT 129 WB, Middlesex, MA
Built 1949 Load: 24.5 t ADT: 96,021
HWY NEWHALL ST
FairOver: WATER RIVER MEADOW BROOK
.16 KM E. OF RT. 3A, Middlesex, MA
Built 1949 Load: 24.6 t ADT: 2,300
HWY NEWTON ST
FairOver: RR MBTA/BMRR
0.16 KM SOUTH JCT RT 20, Middlesex, MA
Built 1930 Load: 24.7 t ADT: 8,400
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.