County profile · official public datasets

Frederick County, MD

486 public highway bridges tracked in the FHWA National Bridge Inventory: 43.2% rated Good, 54.1% Fair, 2.7% Poor.

486
Public bridges
43.2%
Good condition
2.7%
Poor condition

The verdict

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

Frederick County posts a top-quartile lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 25%
lowest Poor share in state
2.7%
Poor-condition share
486
public highway bridges
1971
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.

Frederick County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Frederick County ranks #6 of 24 Maryland counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.7%). Frederick County, Maryland contains 486 public highway bridges. Roughly 43.2% are rated “Good,” 54.1% “Fair,” and 2.7% “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

486

Public highway bridges in Frederick County

Good condition

43.2%

210 of 486 rated 7-9

Fair condition

54.1%

263 of 486 rated 5-6

Poor condition

2.7%

13 of 486 rated 4 or below

In-state Poor-share rank

#6 of 24

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

Condition distribution

Share of 486 NBI-tracked bridges by lowest applicable component rating.

Good
43.2% (210)
Fair
54.1% (263)
Poor
2.7% (13)

Frederick County's Poor-condition bridges carry 17,033 vehicle crossings a day

That is 0.3% of the county's reported daily bridge traffic on 2.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,310 crossings a day against 7,809 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 486 of 486 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

47.5% of Frederick County's bridges have passed the 50-year mark

231 of the 486 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 43.2% 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 39.6% of the county's Poor-condition bridge traffic

SHOOKSTOWN ROAD over CARROLL CREEK, built 1911, carries 6,750 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 13-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 17,033 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Frederick County's bridges were built

486 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1980s, when 104 of the county's bridges still in the inventory were built, which is 21.4% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1971) matches the Maryland average (1972).

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

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

The 5 Maryland counties nearest Frederick County in number of bridges, with their condition splits. Its 2.7% Poor share is the 2nd-lowest of these 6. Its average build year of 1971 against a peer-group mean of 1975 is in line with the group.

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

Bridge inventory size and condition shares for Frederick County and the 5 Maryland counties closest to it in inventory size
County Bridges Poor
Prince George's County 576 3.1%
Montgomery County 515 4.9%
Frederick County (this page) 486 2.7%
Anne Arundel County 389 1.5%
Baltimore city County 374 8.6%
Howard County 309 5.8%

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

Similar inventory size

Nearest county inventories outside MD (486 bridges here).

Similar average build year

Nearest mean year-built outside MD (1971 here).

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

All 486 Good 210 Fair 263 Poor 13

Fair-condition bridges (263)

US 340 EBR

Fair

Over: MD 180 WBR

0.07 MILE EAST OF MD 180, Frederick, MD

Built 1964 Load: 46.7 t ADT: 23,492

US 15 NBR

Fair

Over: MD 77 HUNTING CREEK

0.46 MILE SOUTH OF MD 15D, Frederick, MD

Built 1957 Load: 46.7 t ADT: 30,410

IS 70 EBR

Fair

Over: US 15

0.37 MILE EAST OF MD 180, Frederick, MD

Built 1968 Load: 47.2 t ADT: 89,580

REICHS FORD ROAD

Fair

Over: MONOCACY RIVER

1.5 MILES SOUTH OF I-70, Frederick, MD

Built 1973 Load: 47.2 t ADT: 3,711

LINKS BRIDGE ROAD

Fair

Over: MONOCACY RIVER

0.18 MI W OF DUBLIN ROAD, Frederick, MD

Built 1980 Load: 47.2 t ADT: 1,620

IS 270 NB

Fair

Over: BAKER VALLEY RD

2.96 MILES NORTH OF MD 80, Frederick, MD

Built 1950 Load: 47.6 t ADT: 80,340

IS 270 SB

Fair

Over: BAKER VALLEY RD

2.96 MILES NORTH OF MD 80, Frederick, MD

Built 1950 Load: 47.6 t ADT: 80,340

US 15 NBR

Fair

Over: US 40/W. PATRICK STREET

1.09 MILES N OF MD 180, Frederick, MD

Built 1958 Load: 47.6 t ADT: 95,190

US 15 SBR

Fair

Over: US 40/W. PATRICK STREET

1.09 MILES N OF MD 180, Frederick, MD

Built 1958 Load: 47.6 t ADT: 95,190

ROCKY RIDGE ROAD (

Fair

Over: MONOCACY RIVER

1.3 MI W OF CARROLL CO, Frederick, MD

Built 1932 Load: 48.1 t ADT: 937

IS 70 WBR

Fair

Over: MONUMENT ROAD

1.59 MILES E OF WASH CO, Frederick, MD

Built 1968 Load: 48.1 t ADT: 83,710

MD 75

Fair

Over: IS 70

0.24 MI S OF MD 144FB, Frederick, MD

Built 1973 Load: 48.1 t ADT: 9,752

IS 70 EBR

Fair

Over: BILL MOXELY ROAD

1.73 MI W OF CARROLL CO, Frederick, MD

Built 1974 Load: 48.1 t ADT: 69,020

IS 70 WBR

Fair

Over: BILL MOXELY ROAD

1.73 MI W OF CARROLL CO, Frederick, MD

Built 1974 Load: 48.1 t ADT: 69,020

I 70 RAMP B (4)

Fair

Over: MD 180

I-70/MD 351 INTERCHANGE, Frederick, MD

Built 1996 Load: 48.1 t ADT: 12,602

US 15 NBR

Fair

Over: ROSEMONT AVE

0.77 MILE NORTH OF US 40, Frederick, MD

Built 1958 Load: 49.0 t ADT: 93,930

MD 17

Fair

Over: US 340

0.15 MILE NORTH OF MD 180, Frederick, MD

Built 1964 Load: 49.0 t ADT: 2,061

IS 70 WBR

Fair

Over: HOLLOW ROAD

0.1 M W OF RIDGE ROAD, Frederick, MD

Built 1968 Load: 49.0 t ADT: 68,230

IS 70 EBR

Fair

Over: MT TABOR ROAD

1.15 MILES WEST OF MD 17, Frederick, MD

Built 1968 Load: 49.4 t ADT: 71,007

MD 140

Fair

Over: US 15

0.16 MI S OF MD 904F, Frederick, MD

Built 1971 Load: 49.4 t ADT: 9,010

N. BENTZ STREET

Fair

Over: CARROLL CREEK

365 NORTH OF MD 144, Frederick, MD

Built 1992 Load: 49.9 t ADT: 7,250

IS 70 EB

Fair

Over: CSX TRANS.

.09 M E OF BILL MOXLEY RD, Frederick, MD

Built 1954 Load: 50.8 t ADT: 67,891

IS 270 NB

Fair

Over: BENNETT CREEK

1.26 MI. N. OF MD 80, Frederick, MD

Built 1950 Load: 50.8 t ADT: 88,192

IS 270 SB

Fair

Over: BENNETT CREEK

1.26 MI. N. OF MD 80, Frederick, MD

Built 1950 Load: 50.8 t ADT: 88,192

US 340 EBR

Fair

Over: S MOUNTAIN ROAD

0.27 MILE EAST OF MD 180, Frederick, MD

Built 1964 Load: 50.8 t ADT: 23,492

IS 70 WBR

Fair

Over: MT TABOR ROAD

1.15 MILES WEST OF MD 17, Frederick, MD

Built 1968 Load: 50.8 t ADT: 71,007

IS 70 WB

Fair

Over: CSX TRANS.

.09 M E OF BILL MOXLEY RD, Frederick, MD

Built 1954 Load: 51.2 t ADT: 67,891

MUSSETTER ROAD

Fair

Over: IS 70

2.11 MI W OF MD 75, Frederick, MD

Built 1973 Load: 51.2 t ADT: 691

IS 270

Fair

Over: BRANCH OF BENNETT CREEK

0.21 M S OF BR NO 1017900, Frederick, MD

Built 1951 Load: 51.2 t ADT: 86,751

US 340 EBR

Fair

Over: US 15 SBR

4.33 MILES EAST OF MD 180, Frederick, MD

Built 1966 Load: 51.7 t ADT: 32,282

IJAMSVILLE ROAD

Fair

Over: BUSH CREEK

1.2 MI N OF MD RTE 80, Frederick, MD

Built 2016 Load: 51.7 t ADT: 3,667

MD 77

Fair

Over: HUNTING CREEK

0.29 MILE WEST OF US 15, Frederick, MD

Built 1970 Load: 52.6 t ADT: 4,351

MD 180

Fair

Over: IS 70

0.49 MILE WEST OF US 15, Frederick, MD

Built 1968 Load: 52.6 t ADT: 3,850

US 15 NBR

Fair

Over: TOMS CREEK

0.65 MILE N OF US 15BU, Frederick, MD

Built 1980 Load: 52.6 t ADT: 18,340

IS 70 EBR

Fair

Over: HOLLOW ROAD

0.1 M W OF RIDGE ROAD, Frederick, MD

Built 1968 Load: 53.1 t ADT: 68,230

IS 70 EBR

Fair

Over: IS 70 RAMP E

0.28 MILE WEST OF US 40AL, Frederick, MD

Built 1969 Load: 53.1 t ADT: 68,800

MD 75

Fair

Over: BENNETT CREEK

1.62 MILES N OF MD 355, Frederick, MD

Built 1974 Load: 53.5 t ADT: 7,952

US 15 SBR

Fair

Over: MD 26

0.15 MILE NORTH OF MD 26, Frederick, MD

Built 1968 Load: 53.5 t ADT: 42,640

IS 70 EBR & RAMP L

Fair

Over: IS 270

0.09 M W OF BR NO 1012200, Frederick, MD

Built 1955 Load: 54.0 t ADT: 83,731

TIMMONS ROAD

Fair

Over: LINGANORE CREEK

AT GLISSANS MILL RD INT, Frederick, MD

Built 1974 Load: 54.4 t ADT: 276

MD 144FA

Fair

Over: IS 70

0.38 M W OF KING AVENUE, Frederick, MD

Built 1984 Load: 55.3 t ADT: 11,771

IS 70 WBR

Fair

Over: US 15

0.37 MILE EAST OF MD 180, Frederick, MD

Built 1968 Load: 55.3 t ADT: 89,580

OLD FREDERICK ROAD

Fair

Over: HUNTING CREEK

1.5 MILES SOUTH OF MD 550, Frederick, MD

Built 1995 Load: 55.3 t ADT: 3,445

IS 70 EBR

Fair

Over: IS 70 RAMP A

0.28 MILE EAST OF MD 180, Frederick, MD

Built 1968 Load: 56.2 t ADT: 78,360

MD 806A

Fair

Over: HIGH RUN

0.41 MILE NORTH OF US 15G, Frederick, MD

Built 1950 Load: 56.7 t ADT: 1,072

STOTTLEMYER ROAD

Fair

Over: MIDDLE CREEK

0.1 MI NE OF MD 17, Frederick, MD

Built 1977 Load: 56.7 t ADT: 1,456

PETERSVILLE ROAD

Fair

Over: LITTLE CATOCTIN CREEK

0.61 MI N OF MD 871G, Frederick, MD

Built 1941 Load: 57.6 t ADT: 3,270

MD 180

Fair

Over: US 340

0.13 MILE WEST OF MD 872, Frederick, MD

Built 1964 Load: 57.6 t ADT: 4,460

IS 70 WBR

Fair

Over: IS 70 RAMP A

0.28 MILE EAST OF MD 180, Frederick, MD

Built 1968 Load: 57.6 t ADT: 78,360

IS 70 EBR

Fair

Over: CATOCTIN CREEK

0.60 MILE EAST OF MD 17, Frederick, MD

Built 1968 Load: 59.4 t ADT: 68,230

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.