County profile · official public datasets

Carroll County, MD

205 public highway bridges tracked in the FHWA National Bridge Inventory: 28.3% rated Good, 66.3% Fair, 5.4% Poor.

205
Public bridges
28.3%
Good condition
5.4%
Poor condition

The verdict

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

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

15th
of 24 on Poor share
5.4%
Poor-condition share
205
public highway bridges
1968
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.

Carroll County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Carroll County ranks #15 of 24 Maryland counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.4%). Carroll County, Maryland contains 205 public highway bridges. Roughly 28.3% are rated “Good,” 66.3% “Fair,” and 5.4% “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

205

Public highway bridges in Carroll County

Good condition

28.3%

58 of 205 rated 7-9

Fair condition

66.3%

136 of 205 rated 5-6

Poor condition

5.4%

11 of 205 rated 4 or below

In-state Poor-share rank

#15 of 24

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

Condition distribution

Share of 205 NBI-tracked bridges by lowest applicable component rating.

Good
28.3% (58)
Fair
66.3% (136)
Poor
5.4% (11)

Carroll County's Poor-condition bridges carry 28,687 vehicle crossings a day

That is 3% of the county's reported daily bridge traffic on 5.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 2,608 crossings a day against 4,702 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 204 of 205 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

54.1% of Carroll County's bridges have passed the 50-year mark

111 of the 205 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 28.3% 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 70.4% of the county's Poor-condition bridge traffic

MD 26 over LIBERTY RESERVOIR, built 1954, carries 20,192 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 11-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 28,687 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Carroll County's bridges were built

205 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1970s, when 53 of the county's bridges still in the inventory were built, which is 25.9% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1968) matches the Maryland average (1972).

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

How Carroll County compares with Maryland's closest counties by inventory size

The 5 Maryland counties nearest Carroll County in number of bridges, with their condition splits. Its 5.4% Poor share is the 4th-lowest of these 6. Its average build year of 1968 against a peer-group mean of 1968 is in line with the group.

Showing the 5 closest of 23 Maryland counties eligible for comparison.

Bridge inventory size and condition shares for Carroll County and the 5 Maryland counties closest to it in inventory size
County Bridges Poor
Washington County 300 4.7%
Harford County 275 4.7%
Allegany County 245 6.1%
Carroll County (this page) 205 5.4%
Cecil County 193 4.1%
Garrett County 139 11.5%

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

Similar inventory size

Nearest county inventories outside MD (205 bridges here).

Similar average build year

Nearest mean year-built outside MD (1968 here).

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

All 205 Good 58 Fair 136 Poor 11

Fair-condition bridges (136)

TRACEYS MILL ROAD

Fair

Over: SOUTH BR GUNPOWDER FALLS

0.44 MI, Carroll, MD

Built 1978 Load: 34.5 t ADT: 1,104

MD 77

Fair

Over: BIG PIPE CREEK

1.52 MILE WEST OF MD 194, Carroll, MD

Built 1977 Load: 35.4 t ADT: 841

GRAVE RUN ROAD

Fair

Over: GUNPOWDER FALLS

0.14 MI N OF ROLLER ROAD, Carroll, MD

Built 1970 Load: 36.3 t ADT: 660

MD 97

Fair

Over: SOUTH BRANCH PATAPSCO RI

ON HOWARD CO LINE, Carroll, MD

Built 1973 Load: 36.7 t ADT: 8,770

TWIN ARCH ROAD

Fair

Over: SOUTH BR PATAPSCO RIVER

ON HOWARD COUNTY LINE, Carroll, MD

Built 1900 Load: 36.9 t ADT: 98

SPRINGDALE RD

Fair

Over: LITTLE PIPE CREEK

1.09 MILES N OF MD 31, Carroll, MD

Built 1900 Load: 37.2 t ADT: 457

MAYBERRY ROAD

Fair

Over: BIG PIPE CREEK

0.06 MI N OF UNGER RD, Carroll, MD

Built 1987 Load: 37.6 t ADT: 762

OTTERDALE MILL ROA

Fair

Over: BIG PIPE CREEK

0.25 MI S OF NASBAUM RD, Carroll, MD

Built 1930 Load: 37.6 t ADT: 1,268

CARROLLTON ROAD

Fair

Over: DEEP RUN

0.02 MI W OF LEES MILL RD, Carroll, MD

Built 1960 Load: 37.6 t ADT: 709

MD 75

Fair

Over: LITTLE PIPE CREEK

0.18 MI S OF UNION BRIDGE, Carroll, MD

Built 1922 Load: 39.0 t ADT: 4,051

MD 496

Fair

Over: BR OF BIG PIPE CREEK

3.03 MI E OF MD 97, Carroll, MD

Built 1931 Load: 39.5 t ADT: 4,042

NORTH TANNERY ROAD

Fair

Over: WEST BR PATAPSCO RIVER

0.8 MI W OF GORSUCH ROAD, Carroll, MD

Built 1974 Load: 39.5 t ADT: 200

NAYLORS MILL ROAD

Fair

Over: BIG PIPE CREEK

0.41 MI N OF MD 77, Carroll, MD

Built 1947 Load: 39.9 t ADT: 24

NINER ROAD

Fair

Over: SOUTH BRANCH MIDDLE RUN

0.59 MI N OF MD 32, Carroll, MD

Built 1974 Load: 39.9 t ADT: 756

HAPES MILL ROAD

Fair

Over: BIG PIPE CREEK

1 MI E CROUSE MILL RD, Carroll, MD

Built 1974 Load: 40.4 t ADT: 102

ADAMS MILL ROAD

Fair

Over: LITTLE PIPE CREEK

.03 MI E OF ROOPS MILL RD, Carroll, MD

Built 1974 Load: 40.8 t ADT: 75

MD 850C

Fair

Over: TALBOT BRANCH

0.03 M S OF FRANKLIN RD, Carroll, MD

Built 1931 Load: 41.7 t ADT: 999

MD 27

Fair

Over: MORGAN RUN

1.68 MILE NORTH OF MD 407, Carroll, MD

Built 1922 Load: 42.2 t ADT: 14,091

SAMS CREEK ROAD

Fair

Over: SAMS CREEK

0.2 M S OF MARSTON ROAD, Carroll, MD

Built 1989 Load: 42.6 t ADT: 906

RUNKLES ROAD

Fair

Over: MIDDLE RUN

0.57 MI N OF BOTELER RD, Carroll, MD

Built 1966 Load: 42.6 t ADT: 589

EDEN MILL ROAD

Fair

Over: TUCKERS BRANCH

0.27 MI WEST OF MD 97, Carroll, MD

Built 1969 Load: 42.6 t ADT: 1,535

CLEAR VIEW ROAD

Fair

Over: MEADOW BRANCH

1.15 MILES S OF MD 832, Carroll, MD

Built 1984 Load: 43.5 t ADT: 192

SHILOH ROAD

Fair

Over: EAST BRANCH PATAPSCO RIV

0.05 MI W OF BRODBECK RD, Carroll, MD

Built 1969 Load: 43.5 t ADT: 1,327

GREEN STREET

Fair

Over: MD MIDLAND RAILWAY

WESTMINSTER MD, Carroll, MD

Built 1923 Load: 43.5 t ADT: 7,436

KEYSVILLE-FREDERIC

Fair

Over: MONOCACY RIVER

ON FRED CO LINE, Carroll, MD

Built 1900 Load: 44.0 t ADT: 260

MD 496

Fair

Over: BEAR BRANCH

0.76 MILE EAST OF MD 97, Carroll, MD

Built 1931 Load: 44.9 t ADT: 4,042

ROOP ROAD

Fair

Over: PINEY CREEK

.7 M SE OF BULLFROG RD, Carroll, MD

Built 1912 Load: 45.4 t ADT: 317

HUGHES ROAD

Fair

Over: BEAVER RUN

0.23 MI WEST OF MD 91, Carroll, MD

Built 1976 Load: 45.4 t ADT: 330

HARNEY ROAD

Fair

Over: PINEY CREEK

0.60 MI N OF MD 140, Carroll, MD

Built 1958 Load: 45.8 t ADT: 2,818

HALTER ROAD

Fair

Over: BIG PIPE CREEK

0.12 MI N OF STUDY RD, Carroll, MD

Built 1966 Load: 46.3 t ADT: 669

COON CLUB ROAD

Fair

Over: EAST BRANCH PATAPSCO RIV

0.15 MI E OF HOUCK RD, Carroll, MD

Built 1964 Load: 46.7 t ADT: 2,650

MD 832

Fair

Over: BIG PIPE CREEK

1.02 MILE NORTH OF MD 140, Carroll, MD

Built 1929 Load: 47.2 t ADT: 1,662

BUCKHORN ROAD

Fair

Over: BUCKHORN RUN

0.75 MI E OF FRETER ROAD, Carroll, MD

Built 1952 Load: 47.2 t ADT: 694

BRANGELS ROAD

Fair

Over: PINEY RUN

0.55 MI E OF ARRINGTON RD, Carroll, MD

Built 1974 Load: 48.5 t ADT: 3,125

IS 70 EB

Fair

Over: MD 27

0.03 MI E OF FREDERICK CO, Carroll, MD

Built 1974 Load: 49.4 t ADT: 65,550

IS 70 WB

Fair

Over: MD 27

0.03 MI E OF FREDERICK CO, Carroll, MD

Built 1974 Load: 49.4 t ADT: 65,550

MD 482

Fair

Over: CSX TRANSPORTATION

0.151 MILE WEST OF MD 20, Carroll, MD

Built 1982 Load: 49.4 t ADT: 8,632

MD 854B

Fair

Over: MORGAN RUN

3.63 MILE SOUTH OF MD 32, Carroll, MD

Built 1983 Load: 49.4 t ADT: 1,970

MD 194

Fair

Over: PINEY CREEK

.61 MILE SOUTH OF MD 194E, Carroll, MD

Built 1958 Load: 51.2 t ADT: 4,982

CROUSE MILL ROAD

Fair

Over: BIG PIPE CREEK

.15 MI S OF SHARRETT ROAD, Carroll, MD

Built 1976 Load: 51.7 t ADT: 668

WOODBINE ROAD

Fair

Over: SOUTH BRANCH PATAPSCO RI

ON HOWARD CO LINE, Carroll, MD

Built 1976 Load: 52.6 t ADT: 8,182

GREEN MILL ROAD

Fair

Over: BEAVER RUN

1.02 MILES SW OF MD 140, Carroll, MD

Built 1976 Load: 53.5 t ADT: 1,291

MD 26

Fair

Over: LIBERTY RESERVOIR

1.04 M W OF BALTO CO LINE, Carroll, MD

Built 1954 Load: 54.0 t ADT: 20,192

MD 852H

Fair

Over: WEST BRANCH PATAPSCO RIV

0.02 MILE WEST OF MD 852G, Carroll, MD

Built 1911 Load: 54.9 t ADT: 999

ARTERS MILL ROAD

Fair

Over: BIG PIPE CREEK

1.01 MI N OF STONE ROAD, Carroll, MD

Built 1982 Load: 54.9 t ADT: 247

BASEHORES MILL RD

Fair

Over: BIG PIPE CREEK

0.02 MI NW OF UNGER RD, Carroll, MD

Built 1981 Load: 55.3 t ADT: 669

STARNERS DAM ROAD

Fair

Over: MONOCACY RIVER

ON FRED CO LINE, Carroll, MD

Built 1918 Load: 55.8 t ADT: 36

FRINGER ROAD

Fair

Over: PINEY CREEK

0.08 MI N OF MD 194, Carroll, MD

Built 1930 Load: 56.2 t ADT: 326

LOUISVILLE ROAD

Fair

Over: MIDDLE RUN

0.60 MI S OF DEER PARK RD, Carroll, MD

Built 1974 Load: 56.2 t ADT: 988

MD 140

Fair

Over: RICHARDSON RD

2.69 MILE NORTH OF MD 832, Carroll, MD

Built 1963 Load: 56.7 t ADT: 13,070

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.