County profile · official public datasets

Plymouth County, MA

287 public highway bridges tracked in the FHWA National Bridge Inventory: 30.7% rated Good, 63.4% Fair, 5.9% Poor.

287
Public bridges
30.7%
Good condition
5.9%
Poor condition

The verdict

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

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

Top 31%
lowest Poor share in state
5.9%
Poor-condition share
287
public highway bridges
1960
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.

Plymouth County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Plymouth County ranks #4 of 13 Massachusetts counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.9%). Plymouth County, Massachusetts contains 287 public highway bridges. Roughly 30.7% are rated “Good,” 63.4% “Fair,” and 5.9% “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

287

Public highway bridges in Plymouth County

Good condition

30.7%

88 of 287 rated 7-9

Fair condition

63.4%

182 of 287 rated 5-6

Poor condition

5.9%

17 of 287 rated 4 or below

In-state Poor-share rank

#4 of 13

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

Condition distribution

Share of 287 NBI-tracked bridges by lowest applicable component rating.

Good
30.7% (88)
Fair
63.4% (182)
Poor
5.9% (17)

Plymouth County's Poor-condition bridges carry 293,076 vehicle crossings a day

That is 5.8% of the county's reported daily bridge traffic on 5.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 17,240 crossings a day against 14,834 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 286 of 287 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

67.9% of Plymouth County's bridges have passed the 50-year mark

195 of the 287 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 30.7% 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 24.2% of the county's Poor-condition bridge traffic

HWY CENTRAL ST over WATER SHUMATUSCACANT RIV, built 1956, carries 71,009 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 17-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 293,076 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Plymouth County's bridges were built

287 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1950s, when 62 of the county's bridges still in the inventory were built, which is 21.6% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year (1960) matches the Massachusetts average (1961).

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

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

The 5 Massachusetts counties nearest Plymouth County in number of bridges, with their condition splits. Its 5.9% Poor share is the 2nd-lowest of these 6. Its average build year of 1960 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 Plymouth County and the 5 Massachusetts counties closest to it in inventory size
County Bridges Poor
Essex County 395 17.2%
Bristol County 384 6.5%
Norfolk County 343 5%
Franklin County 314 11.1%
Plymouth County (this page) 287 5.9%
Hampshire County 259 8.9%

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 Plymouth 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 Plymouth County, both outside Massachusetts so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside MA (287 bridges here).

Similar average build year

Nearest mean year-built outside MA (1960 here).

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

All 287 Good 88 Fair 182 Poor 17

All bridges (287)

HWY SEA ST

Good

Over: WATER SOUTH RIVER

MARSHFIELD-SCITUATE LINE, Plymouth, MA

Built 2010 Load: 54.9 t ADT: 4,009

HWY SOUTH ST

Good

Over: WATER TOWN RIVER

ADJACENT TO RIVER AVE, Plymouth, MA

Built 2008 Load: 55.6 t ADT: 7,888

ST 3 NB/PLGRM HWY

Good

Over: WATER EEL RIVER

4.25 M S OF RTE 44, Plymouth, MA

Built 1955 Load: 55.7 t ADT: 45,000

ST 3 SB/PLGRM HWY

Good

Over: WATER EEL RIVER

4.25 M S OF RTE 44, Plymouth, MA

Built 1955 Load: 55.7 t ADT: 43,577

HWY PERKINS AVE

Good

Over: WATER SALISBURY PLAIN R

.25 MI E OF RTE 28, Plymouth, MA

Built 1995 Load: 56.4 t ADT: 7,629

HWY ALLEN ST

Good

Over: WATER SALISBURY BROOK

AT MAIN ST, Plymouth, MA

Built 2002 Load: 57.0 t ADT: 2,068

HWY HIGHLAND RD

Good

Over: ST140 NB

1.2 MI NE OF COUNTY ST, Plymouth, MA

Built 1958 Load: 57.3 t ADT: 10,300

HWY SUMMER ST

Good

Over: RR MBTA/CSX

.2 MI W OF FLAGG ST, Plymouth, MA

Built 1984 Load: 58.1 t ADT: 4,100

HWY ELM ST

Good

Over: WATER JONES RIVER

.15 MI S OF RTE 27, Plymouth, MA

Built 2014 Load: 58.3 t ADT: 5,043

HWY STATE ST

Good

Over: WATER INDIAN HEAD RIVER

AT HANOVER LINE, Plymouth, MA

Built 1995 Load: 60.2 t ADT: 4,397

HWY HIGHLAND RD

Good

Over: ST140 SB

1.2 MI NE OF COUNTY ST, Plymouth, MA

Built 1969 Load: 60.7 t ADT: 10,300

ST 25 EB

Good

Over: WATER MILL POND

.1 M W OF GLEN CHARLIE RD, Plymouth, MA

Built 1981 Load: 61.0 t ADT: 38,664

ST106 WAPPING RD

Good

Over: WATER JONES RIVER

1.2 MI WEST OF ST 3 A, Plymouth, MA

Built 1971 Load: 62.3 t ADT: 7,800

ST123 BELMONT ST

Good

Over: ST 24

.1 MI W OF VA HOSPITAL, Plymouth, MA

Built 1954 Load: 62.5 t ADT: 29,214

HWY JULIAN ST

Good

Over: WATER SOUTH RIVER

EAST OF BAYBERRY ROAD, Plymouth, MA

Built 2010 Load: 66.4 t ADT: 786

HWY TAYLOR AVE

Good

Over: WATER BEAVER DAM BROOK

.1MI W OF SHORT ST, Plymouth, MA

Built 2019 Load: 74.5 t ADT: 3,800

HWY FOREST ST

Good

Over: WATER SALISBURY PLAIN R

.1 MI SOUTH OF PERKINS ST, Plymouth, MA

Built 1999 Load: 78.8 t ADT: 714

HWY COUNTRY WAY

Good

Over: WATER BOUND BROOK

0.125 KM NW OF GANNETT RD, Plymouth, MA

Built 2008 Load: 79.6 t ADT: 5,560

HWY BROADWAY

Good

Over: WATER INDIAN HEAD RIVER

AT HANSON LINE, Plymouth, MA

Built 2010 Load: 99.9 t ADT: 12,543

US 6 EB/ST28 SB

Good

Over: WATER AGAWAM RIVER

.2 MI W OF DEPOT ST, Plymouth, MA

Built 1949 Load: 99.9 t ADT: 28,448

HWY FOREST ST

Poor

Over: WATER TOWN RIVER

.01 M FROM RIVER ST, Plymouth, MA

Built 1968 Load: 0.0 t ADT: 776

HWY POWDER PT AV

Poor

Over: WATER DUXBURY BAY

1 MI E OF WASHINGTON ST, Plymouth, MA

Built 1987 Load: 5.9 t ADT: 1,950

HWY WEST ST

Poor

Over: ST 24

.8 MI NORTH OF ST106, Plymouth, MA

Built 1953 Load: 18.4 t ADT: 5,571

HWY WALNUT ST

Poor

Over: ST 24

.2 MI EAST OF MANLEY ROAD, Plymouth, MA

Built 1953 Load: 21.0 t ADT: 1,966

US 6 MARION RD

Poor

Over: WATER WEWEANTIC RIVER

2 MI E OF RTE 105, Plymouth, MA

Built 1929 Load: 23.6 t ADT: 8,832

HWY RIVER ST

Poor

Over: HWY PLIMOTH PLNTN HWY

1.13 KM W OF RTE 3A, Plymouth, MA

Built 1951 Load: 24.6 t ADT: 5,200

ST 3 NB

Poor

Over: WATER NORTH RIVER

AT NORWELL PEMBROKE TL, Plymouth, MA

Built 1961 Load: 24.9 t ADT: 37,081

ST 3 SB

Poor

Over: WATER NORTH RIVER

AT NORWELL PEMBROKE TL, Plymouth, MA

Built 1961 Load: 24.9 t ADT: 32,900

HWY FEARING HILL

Poor

Over: WATER WEWEANTIC RIVER

JUST N OF HORSESHOE POND, Plymouth, MA

Built 1900 Load: 25.4 t ADT: 9,300

HWY VERNON ST

Poor

Over: WATER TAUNTON RIVER

BWATER/MIDDLEBORO LINE, Plymouth, MA

Built 1956 Load: 28.8 t ADT: 1,930

US 6 WAREHAM ROAD

Poor

Over: WATER WEWEANTIC RIVER

AT WAREHAM MARION TL, Plymouth, MA

Built 1929 Load: 28.8 t ADT: 11,379

ST 3 NB/PLGRM HWY

Poor

Over: HWY FRANKLIN ST

2 MI E OF PEMBROKE TL, Plymouth, MA

Built 1962 Load: 32.1 t ADT: 34,314

ST 3 SB/PLGRM HWY

Poor

Over: HWY FRANKLIN ST

2 MI E OF PEMBROKE TL, Plymouth, MA

Built 1962 Load: 32.1 t ADT: 35,142

HWY TIHONET RD

Poor

Over: ST 25

0.7 M E OF RTE 195, Plymouth, MA

Built 1967 Load: 32.2 t ADT: 1,071

US 44 HARDING ST

Poor

Over: RR MBTA/CSX

.5 M W OF EVERETT ST, Plymouth, MA

Built 1963 Load: 33.0 t ADT: 31,681

HWY CENTRAL ST

Poor

Over: WATER SHUMATUSCACANT RIV

.5 MI E OF RTE 18, Plymouth, MA

Built 1956 Load: 42.8 t ADT: 71,009

HWY POND STREET

Poor

Over: WATER SATUCKET RIVER

1 MI. EAST OF ST 106, Plymouth, MA

Built 1850 Load: 45.8 t ADT: 2,974

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

Related

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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.