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.

Fair-condition bridges (182)

ST 3 A/MAIN ST

Fair

Over: WATER TOWN BROOK

.5 M S OF RTE 44, Plymouth, MA

Built 1908 Load: 47.0 t ADT: 8,357

I 495

Fair

Over: RR MBTA/CSX QNB 20.82

CSX TRACK MP QNB 20.82, Plymouth, MA

Built 1958 Load: 47.8 t ADT: 47,237

ST 27 CRESCENT ST

Fair

Over: WATER TROUT BROOK

0.6 M E OF RTE 28, Plymouth, MA

Built 1976 Load: 48.3 t ADT: 14,353

ST 37 HOWARD ST

Fair

Over: RR MBTA/CSX

ADJACENT TO JCT ST 28, Plymouth, MA

Built 1997 Load: 49.1 t ADT: 21,983

ST 3 A/WARREN AVE

Fair

Over: WATER EEL RIVER

3 M S OF RTE 44, Plymouth, MA

Built 1958 Load: 50.0 t ADT: 7,286

HWY ONSET AVE

Fair

Over: WATER EAST RIVER

0.5 MI W OF RTE 6 & 28, Plymouth, MA

Built 1914 Load: 50.0 t ADT: 11,767

ST 28 W GROVE ST

Fair

Over: RR MBTA/CSX

TAUNTON TRACKS MP#34.894, Plymouth, MA

Built 1850 Load: 50.9 t ADT: 17,000

HWY CHERRY ST

Fair

Over: WATER TAUNTON RIVER

.35 MI WEST OF WALNUT ST, Plymouth, MA

Built 2002 Load: 51.4 t ADT: 1,034

HWY SUMMER ST

Fair

Over: WATER TROUT BROOK

AT JCT GROVE ST, Plymouth, MA

Built 1976 Load: 51.8 t ADT: 5,928

ST 3 NB PLGRM HWY

Fair

Over: ST228 HINGHAM ST

.4 M S OF HINGHAM TL, Plymouth, MA

Built 1960 Load: 52.5 t ADT: 72,284

ST 3 SB PLGRM HWY

Fair

Over: ST228 HINGHAM ST

0.4 M S OF HINGHAM TL, Plymouth, MA

Built 1960 Load: 52.5 t ADT: 54,310

ST 3 A/LINCOLN ST

Fair

Over: WATER BACK RIVER

AT HINGHAM WEYMOUTH TL, Plymouth, MA

Built 1943 Load: 54.7 t ADT: 36,300

HWY ADAMS ST

Fair

Over: WATER SHUMATUSCACANT RIV

.25 MI. NE. OF RTE. 18, Plymouth, MA

Built 1956 Load: 54.9 t ADT: 4,000

HWY JOS DRIEBEEK

Fair

Over: WATER GREEN HARBOR RIVER

1.06 KM JCT RTE 139, Plymouth, MA

Built 1985 Load: 55.3 t ADT: 1,285

ST 3 A/MAIN ST

Fair

Over: ST 3 PILGRIM HWY

.8 MI N OF PLYMOUTH TL, Plymouth, MA

Built 1948 Load: 55.4 t ADT: 33,491

HWY HIGH ST

Fair

Over: WATER MATFIELD RIVER

0.8 MI EAST OF HAYWARD ST, Plymouth, MA

Built 1886 Load: 56.1 t ADT: 2,286

HWY PICKENS ST

Fair

Over: ST140 SB

1.5 MI SE OF TAUNTON T.L., Plymouth, MA

Built 1969 Load: 57.7 t ADT: 1,300

I 495 NB

Fair

Over: WATER TAUNTON RIVER

AT MIDDLEBORO RAYNHAM TL, Plymouth, MA

Built 1962 Load: 58.3 t ADT: 28,714

ST105 THOMPSON ST

Fair

Over: WATER WINNETUXET RIVER

AT JCT OF PRATT ST, Plymouth, MA

Built 1992 Load: 61.3 t ADT: 6,800

ST105 THOMPSON ST

Fair

Over: WATER BARTLETT BROOK

.4 MI N OF MIDDLEBORO LN, Plymouth, MA

Built 1992 Load: 61.3 t ADT: 9,181

HWY BRIDGE ST

Fair

Over: WATER MATFIELD RIVER

.15 M NE OF HIGH ST, Plymouth, MA

Built 1884 Load: 62.2 t ADT: 2,716

HWY WARREN AVE

Fair

Over: WATER SALISBURY BROOK

.3 MI S OF ST123, Plymouth, MA

Built 1913 Load: 62.8 t ADT: 12,672

HWY PERKINS ST

Fair

Over: WATER SALISBURY BROOK

0.3 MI E OF RT 28, Plymouth, MA

Built 1914 Load: 69.6 t ADT: 2,571

HWY BELMONT ST

Fair

Over: WATER SALISBURY PLAIN R

.1 MI FROM E BRIDGEWATER, Plymouth, MA

Built 1875 Load: 77.7 t ADT: 9,100

HWY PARSONAGE RD

Fair

Over: WATER WINNETUXET RIVER

.6 MI SW OF RTE 58, Plymouth, MA

Built 1973 Load: 87.5 t ADT: 1,357

HWY ACUSHNET RD

Fair

Over: WATER MATTAPOISETT RIVER

.5 KM NW OF RTE I 195, Plymouth, MA

Built 1942 Load: 89.9 t ADT: 2,200

HWY W UNION ST

Fair

Over: WATER MATFIELD RIVER

.6 MI SW RTE 18, Plymouth, MA

Built 1902 Load: 99.9 t ADT: 4,655

HWY BRIDGE ST

Fair

Over: WATER SATUCKET RIVER

.7 MI NO OF JCT 106, Plymouth, MA

Built 1970 Load: 99.9 t ADT: 1,900

HWY WASHNGTON ST

Fair

Over: WATER NORTH RIVER

PEMBROKE-HANOVER TOWNLINE, Plymouth, MA

Built 1904 Load: 99.9 t ADT: 1,786

HWY CHERRY ST

Fair

Over: WATER FALL BROOK

ADJACENT TO I-495, Plymouth, MA

Built 1957 Load: 99.9 t ADT: 3,200

HWY COMMERCE WAY

Fair

Over: HWY PA LANDERS ACCESS

.2MI N OF US44, Plymouth, MA

Built 2003 Load: 99.9 t ADT: 21,000

HWY MAIN ST

Fair

Over: WATER WEWEANTIC RIVER

.8 MI SE OF ROCHESTER, Plymouth, MA

Built 1978 Load: 99.9 t ADT: 1,571
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.