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

All bridges (205)

ARTERS MILL ROAD

Good

Over: SILVER RUN

0.47 MI N OF MAYBERRY RD, Carroll, MD

Built 1986 Load: 37.6 t ADT: 245

CARROLLTON ROAD

Good

Over: WEST BRANCH PATAPSCO RIV

0.09 MI W OF DUTROW ROAD, Carroll, MD

Built 1978 Load: 37.6 t ADT: 1,697

BIXLER CHURCH ROAD

Good

Over: TRIBUTARY TO BIG PIPE CR

0.21 MI. N. OF MD 496, Carroll, MD

Built 1973 Load: 38.6 t ADT: 694

HOUCKSVILLE ROAD

Good

Over: CSX RAILROAD

1 BLOCK WEST OF MD 30, Carroll, MD

Built 2002 Load: 39.0 t ADT: 4,741

MD 30

Good

Over: TRIB TO EAST BRANCH

1.21 M N OF MD 482, Carroll, MD

Built 2007 Load: 40.8 t ADT: 9,450

MURKLE ROAD

Good

Over: BIG PIPE CREEK

0.41 MILES SOUTH OF MD 97, Carroll, MD

Built 2005 Load: 40.8 t ADT: 377

MD 194

Good

Over: BIG PIPE CREEK

0.64 MILE NORTH OF MD 77, Carroll, MD

Built 2005 Load: 43.1 t ADT: 5,152

GREENMOUNT CHURCH

Good

Over: MURPHY RUN

0.3 MILES EAST OF MD 30, Carroll, MD

Built 2010 Load: 43.1 t ADT: 705

SAMS CREEK ROAD

Good

Over: SAMS CREEK

ON FREDERICK CO LINE, Carroll, MD

Built 1986 Load: 43.5 t ADT: 362

NEWPORT ROAD

Good

Over: GILLIS FALLS

0.09 MI N OF HOWARD CO, Carroll, MD

Built 2001 Load: 43.5 t ADT: 86

MD 86

Good

Over: SOUTH BR GUNPOWDER FALLS

0.97 MI S OF PA LINE, Carroll, MD

Built 2020 Load: 43.7 t ADT: 4,337

BEAR RUN ROAD

Good

Over: BEAR BRANCH

2.2 MI W OF MAYBERRY RD, Carroll, MD

Built 1974 Load: 44.0 t ADT: 397

STONE ROAD

Good

Over: SILVER RUN

0.03 MI NW OF MAYBERRY RD, Carroll, MD

Built 1979 Load: 44.4 t ADT: 626

GOOD INTENT ROAD

Good

Over: LITTLE PIPE CREEK

ON FREDERICK CO LINE, Carroll, MD

Built 1977 Load: 44.4 t ADT: 748

HOFFMAN MILL ROAD

Good

Over: TRIBUTARY EAST OF BRANCH

.91 MI W - HOUCKSVILLE RD, Carroll, MD

Built 1974 Load: 46.3 t ADT: 750

WHITE ROCK ROAD

Good

Over: PINEY RUN

1.07 MILES S OF MD 26, Carroll, MD

Built 2017 Load: 48.0 t ADT: 4,226

RICHARDSON ROAD

Good

Over: BEAR BRANCH

1.37 MILES N OF MD 140, Carroll, MD

Built 1991 Load: 48.5 t ADT: 312

SHEPHERDS MILL RD

Good

Over: LITTLE PIPE CREEK

JUST E OF UNION BRIDGE, Carroll, MD

Built 2023 Load: 49.9 t ADT: 613

MD 140 EB

Good

Over: MD 97

0.35 MILE SOUTH OF MD 31, Carroll, MD

Built 2006 Load: 51.2 t ADT: 47,060

MD 140 WB & RAMP B

Good

Over: MD 97

0.35 MILE SOUTH OF MD 31, Carroll, MD

Built 2006 Load: 51.7 t ADT: 47,060

HOUCKSVILLE ROAD

Good

Over: MD 30

HOUCKSVILLE RD OVER MD 30, Carroll, MD

Built 2007 Load: 51.7 t ADT: 4,844

PINEY CREEK ROAD

Good

Over: ALLOWAY CREEK

.7 M N OF BOWERS ROAD, Carroll, MD

Built 1900 Load: 52.2 t ADT: 234

MAYBERRY ROAD

Good

Over: BEAR BRANCH

1.06 MILES N OF MD 140, Carroll, MD

Built 1985 Load: 52.6 t ADT: 762

BOLLINGER ROAD

Good

Over: NORTH MIDDLE RUN

1 MI S OF WESTMNSTR PIKE, Carroll, MD

Built 1974 Load: 54.9 t ADT: 1,836

MD 84

Good

Over: MEADOW BRANCH

1.24 MILE SOUTH OF MD 832, Carroll, MD

Built 2003 Load: 56.2 t ADT: 922

HOOVER MILL ROAD

Good

Over: BIG PIPE CREEK

0.15 MI SW OF EBBVALE RD, Carroll, MD

Built 1984 Load: 56.2 t ADT: 35

MD 30

Good

Over: SHILOH ROAD

2.276 M S OF MD 482, Carroll, MD

Built 2007 Load: 57.1 t ADT: 9,200

MD 140

Good

Over: MD MID RR MD27 WEST BR

0.02 MILE NORTH OF MD 27, Carroll, MD

Built 2006 Load: 58.5 t ADT: 45,521

EMORY ROAD

Good

Over: DEEP RUN

0.38 MI E OF WESLEY ROAD, Carroll, MD

Built 2000 Load: 59.0 t ADT: 150

MD 97

Good

Over: TUCKERS BRANCH

1.02 M S OF BR NO 0306400, Carroll, MD

Built 1976 Load: 62.6 t ADT: 8,770

UNION BRIDGE ROAD

Good

Over: CHERRY BRANCH

UNION BRIDGE ROAD, Carroll, MD

Built 1990 Load: 62.6 t ADT: 1,034

OLD NEW WINDSOR RD

Good

Over: DICKENSON RUN

0.02 MI S OF NEW WINDSOR, Carroll, MD

Built 1987 Load: 63.0 t ADT: 1,058

MD 496

Good

Over: BIG PIPE CREEK

3.52 MILEI WEST OF MD 30, Carroll, MD

Built 2018 Load: 68.0 t ADT: 3,975

MARRIOTTSVILLE RD

Good

Over: SOUTH BR PATAPSCO RIVER

ON HOWARD COUNTY LINE, Carroll, MD

Built 1986 Load: 68.0 t ADT: 12,255

BLACK ROCK ROAD

Good

Over: SOUTH BRANCH GUNPOWDER F

150 FT N OF TRACEYS MILL, Carroll, MD

Built 2001 Load: 72.6 t ADT: 228

ROCKLAND ROAD

Good

Over: LITTLE PIPE CREEK

0.01 MI N OF ROOPS MIL RD, Carroll, MD

Built 1997 Load: 74.4 t ADT: 89

LAWNDALE ROAD

Good

Over: NORTH BRANCH PATAPSCO RI

0.5 MI. W. EMORY ROAD, Carroll, MD

Built 1995 Load: 74.4 t ADT: 1,582

MD 140

Good

Over: PINEY CREEK

0.85 MI N OF TANEYTOWN, Carroll, MD

Built 1997 Load: 76.6 t ADT: 5,340

CHANDLER DRIVE

Good

Over: BEAVER RUN

87 FT SOUTH OF POOLE ROAD, Carroll, MD

Built 1998 Load: 80.3 t ADT: 825

SKIDMORE ROAD

Good

Over: GILLIS FALLS

.2 MI N OF BRADDOCK RD, Carroll, MD

Built 1988 Load: 83.0 t ADT: 360

BUCHER JOHN ROAD

Good

Over: LITTLE PIPE CREEK

0.02 MI W OF UNION BRIDGE, Carroll, MD

Built 1960 Load: 86.6 t ADT: 1,159

MD 854A

Good

Over: LITTLE MORGAN RUN

1.05 MI N OF BUSHEY RD, Carroll, MD

Built 1976 Load: 99.9 t ADT: 647

FRETER ROAD

Good

Over: PINEY RUN

0.40 MI SOUTH OF MD 26, Carroll, MD

Built 2004 Load: 99.9 t ADT: 806

MAHURON ROAD

Good

Over: UNNAMED STREAM

75 FT. S. OLD WEST. PIKE, Carroll, MD

Built 2008 Load: 99.9 t ADT: 320

UPPER BECKLEYSVILL

Poor

Over: MURPHY RUN

0.05 MI E OF GROSS MIL RD, Carroll, MD

Built 1960 Load: 10.9 t ADT: 1,745

MCKINSTRYS MILL RD

Poor

Over: SAMS CREEK

ON FREDERICK CO LINE, Carroll, MD

Built 1972 Load: 17.2 t ADT: 119

OLD KAYS MILL ROAD

Poor

Over: BEAVER RUN

AT HUGHES ROAD, Carroll, MD

Built 1974 Load: 18.1 t ADT: 209

CARROLLTON ROAD

Poor

Over: EAST BRANCH PATAPSCO RIV

0.59 MI E OF RIDGE ROAD, Carroll, MD

Built 1972 Load: 22.7 t ADT: 590

STONE CHAPEL ROAD

Poor

Over: LITTLE PIPE CREEK

0.10 MI W OF AVONDALE RD, Carroll, MD

Built 1930 Load: 25.8 t ADT: 4,612

HUGHES SHOP ROAD

Poor

Over: BEAR BRANCH

0.025 MI N PLEASANT VA, Carroll, MD

Built 1974 Load: 27.7 t ADT: 152

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.