Total bridges
486
Public highway bridges in Frederick County
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.
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
- pre-1900 12
Built before 1900
12 bridges
- 1900s 9
1900–1909
9 bridges
- 1910s 8
1910–1919
8 bridges
- 1920s 23
1920–1929
23 bridges
- 1930s 23
1930–1939
23 bridges
- 1940s 2
1940–1949
2 bridges
- 1950s 37
1950–1959
37 bridges
- 1960s
1960–1969
75 bridges
- 1970s
1970–1979
76 bridges
- 1980s
1980–1989
104 bridges
- 1990s
1990–1999
46 bridges
- 2000s 39
2000–2009
39 bridges
- 2010s 23
2010–2019
23 bridges
- 2020s 9
2020–2029
9 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).
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.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Prince George's County | 576 | 36.6% | 60.2% | 3.1% | 1976 |
| Montgomery County | 515 | 38.8% | 56.3% | 4.9% | 1978 |
| Frederick County (this page) | 486 | 43.2% | 54.1% | 2.7% | 1971 |
| Anne Arundel County | 389 | 32.6% | 65.8% | 1.5% | 1980 |
| Baltimore city County | 374 | 16% | 75.4% | 8.6% | 1964 |
| Howard County | 309 | 35.9% | 58.3% | 5.8% | 1978 |
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).
- St. Clair County, IL · 486 bridges
- Cattaraugus County, NY · 484 bridges
- Black Hawk County, IA · 489 bridges
- Suffolk County, MA · 489 bridges
Similar average build year
Nearest mean year-built outside MD (1971 here).
- Wayne County, MI · avg 1971 · 1,026 bridges
- Washington County, PA · avg 1971 · 655 bridges
- Linn County, OR · avg 1971 · 566 bridges
- Monmouth County, NJ · avg 1971 · 505 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (486)
IS 70 WB
FairOver: CATOCTIN CREEK
0.60 MILE EAST OF MD 17, Frederick, MD
Built 1968 Load: 59.4 t ADT: 68,230
IS 270 SB
FairOver: MD 80
3.52 MILES N OF MONT CO, Frederick, MD
Built 1950 Load: 59.9 t ADT: 81,890
ALBERT STAUB ROAD
FairOver: OWENS CREEK
0.5 M N OF EYLER ROAD, Frederick, MD
Built 1982 Load: 59.9 t ADT: 1,323
MT EPHRAIM ROAD
FairOver: BENNETT CREEK
0.37 MI S OF PARK MILLS R, Frederick, MD
Built 1974 Load: 59.9 t ADT: 260
US 15 SBR
FairOver: MD 550
0.36 MILE NORTH OF MD 15D, Frederick, MD
Built 1982 Load: 60.3 t ADT: 27,210
US 15
FairOver: OWENS CREEK
0.6 MILE NORTH OF MD 550, Frederick, MD
Built 1954 Load: 60.8 t ADT: 27,210
MD 17
FairOver: MIDDLE CREEK
1.64 MILES N0RTH OF US 40, Frederick, MD
Built 1889 Load: 61.2 t ADT: 1,951
SUGARLOAF MTN RD
FairOver: BR OF BENNETT CREEK
0.12 MI S OF THURSTON RD, Frederick, MD
Built 1981 Load: 61.7 t ADT: 133
US 15 SBR
FairOver: MD 77 HUNTING CREEK
0.46 MILE SOUTH OF MD 15D, Frederick, MD
Built 1985 Load: 62.6 t ADT: 30,410
THURSTON ROAD
FairOver: BENNETT CREEK
0.75 MI S OF PETERS RD, Frederick, MD
Built 1964 Load: 63.0 t ADT: 1,632
FOXVLLE DEERFIELD
FairOver: OWENS CREEK
0.25 MI NW OF MD 550, Frederick, MD
Built 1978 Load: 63.0 t ADT: 561
IS 70 WBR
FairOver: IS 70 RAMP E
0.28 MILE WEST OF US 40AL, Frederick, MD
Built 1969 Load: 63.5 t ADT: 68,800
US 15 NBR
FairOver: LITTLE OWENS CREEK
1.74 MILE NORTH OF MD 550, Frederick, MD
Built 1982 Load: 63.5 t ADT: 27,210
S. CARROLL STREET
FairOver: CARROLL CREEK
470 SOUTH OF SR 144, Frederick, MD
Built 1991 Load: 63.5 t ADT: 10,130
MD 77
FairOver: HUNTING CREEK
1.15 M W OF PRYOR ROAD, Frederick, MD
Built 1970 Load: 64.9 t ADT: 3,271
US 15 RAMP J
FairOver: HUNTING CREEK
0.03 MI S OF MD 77, Frederick, MD
Built 1985 Load: 65.3 t ADT: 500
IS 270 NB
FairOver: MD 80
3.52 MILES N OF MONT CO, Frederick, MD
Built 1950 Load: 65.8 t ADT: 81,890
MOUNTAINDALE ROAD
FairOver: FISHING CREEK
AT PUTNAM RD INT, Frederick, MD
Built 1979 Load: 66.2 t ADT: 346
MOUNTAINDALE ROAD
FairOver: LITTLE FISHING CREEK
0.1 MI W OF GAMBRILL PARK, Frederick, MD
Built 1982 Load: 66.7 t ADT: 106
LILY PONS ROAD
FairOver: SMALL STREAM
0.1 MI EAST OF MD RTE 85, Frederick, MD
Built 1976 Load: 67.6 t ADT: 394
SUNDAYS LANE
FairOver: TUSCARORA CREEK
0.25 MI E OPOSSUMTOWN PIK, Frederick, MD
Built 1978 Load: 68.0 t ADT: 505
US 40
FairOver: LITTLE CATOCTIN CREEK
0.2 M E OF HARMONY ROAD, Frederick, MD
Built 1936 Load: 68.9 t ADT: 5,522
DAYSVILLE ROAD
FairOver: ISRAEL CREEK
0.5 MI E OF MD RTE 194, Frederick, MD
Built 1990 Load: 68.9 t ADT: 1,392
CRUM ROAD
FairOver: ISRAEL CREEK
0.5 MI S OF WALKERSVILLE, Frederick, MD
Built 1994 Load: 68.9 t ADT: 3,121
US 15
FairOver: MARYLAND MIDLAND RR
0.26 MILE SOUTH OF MD 550, Frederick, MD
Built 1957 Load: 69.8 t ADT: 28,321
MILT SUMMERS ROAD
FairOver: GRINDSTONE RUN
0.13 MILES WEST OF MD 17, Frederick, MD
Built 1977 Load: 72.6 t ADT: 1,657
LIME PLANT ROAD
FairOver: TRIBUTARY OF BENS BRANCH
0.3 MI W OF DETRICK RD, Frederick, MD
Built 1972 Load: 75.3 t ADT: 128
SUGARLOAF PARKWAY
FairOver: PETER PAN RUN
0.1 MI N OF BUSH CREEK DR, Frederick, MD
Built 2002 Load: 75.7 t ADT: 1,080
NORTH BEACH ROAD
FairOver: HUNTING CREEK
CUNN. FALLS STATE PARK, Frederick, MD
Built 1980 Load: 76.6 t ADT: 100
MILT SUMMERS ROAD
FairOver: TRIB. OF CATOCTIN CREEK
0.3 MI W OF MT TABOR RD, Frederick, MD
Built 1977 Load: 78.5 t ADT: 1,210
US 15 BU
FairOver: FLAT RUN
0.75 MILE SOUTH OF US 15, Frederick, MD
Built 1927 Load: 81.6 t ADT: 1,820
BRICE ROAD
FairOver: MUDDY RUN
0.13 S OF BLUE MTN ROAD, Frederick, MD
Built 1998 Load: 83.0 t ADT: 292
OAKDALE SCHOOL ROA
FairOver: TRIBUTARY TO LONG BRANCH
0.2 MI N OF OLD NATL PIKE, Frederick, MD
Built 2001 Load: 88.0 t ADT: 1,790
MD 17
FairOver: BROAD RUN
0.07 MI N OF ARNOLD ROAD, Frederick, MD
Built 1959 Load: 89.3 t ADT: 2,061
US 15 BU
FairOver: TOMS CREEK
0.23 MILE NORTH OF US 15, Frederick, MD
Built 1923 Load: 99.9 t ADT: 7,680
US 15 & RAMP 8
FairOver: CARROLL CREEK
0.64 MILE NORTH OF US 40, Frederick, MD
Built 1958 Load: 99.9 t ADT: 95,190
MD 26
FairOver: N FORK LINGANORE CREEK
2.53 MI W OF CARROLL CO, Frederick, MD
Built 1950 Load: 99.9 t ADT: 5,272
US 340
FairOver: LITTLE CATOCTIN CREEK
0.36 MILE EAST OF MD 17, Frederick, MD
Built 1964 Load: 99.9 t ADT: 24,600
IS 70
FairOver: GRINDSTONE RUN
0.3 MILE WEST OF MD 17, Frederick, MD
Built 1968 Load: 99.9 t ADT: 70,011
IS 70
FairOver: LONG BRANCH
0.23 M E OF BR NO 1018400, Frederick, MD
Built 1985 Load: 99.9 t ADT: 62,311
MANOR WOODS ROAD
FairOver: TUSCARORA CREEK
0.53 MI E OF BALLENGER CR, Frederick, MD
Built 1970 Load: 99.9 t ADT: 965
WESTVIEW DRIVE
FairOver: QUARRY BRANCH
0.15 MI N OF CRESTWOOD BV, Frederick, MD
Built 2004 Load: 99.9 t ADT: 1,500
OLD FREDERICK ROAD
FairOver: BEAVER BRANCH
2.38 MILES N. OF MD RT 77, Frederick, MD
Built 1975 Load: 99.9 t ADT: 784
APPOLDS ROAD
FairOver: BEAVER BRANCH
0.6 MI WEST OF MD 76, Frederick, MD
Built 1972 Load: 99.9 t ADT: 346
YEAGERTOWN ROAD
FairOver: LOCAL STREAM
1.25 MI NORTH OF MD 144, Frederick, MD
Built 1982 Load: 99.9 t ADT: 3,203
HOFFMAN SEACHRIST
FairOver: DORCUS BRANCH
425 FT SOUTH OF MD 550, Frederick, MD
Built 1963 Load: 99.9 t ADT: 260
LEHIGH ROAD
FairOver: SAMS CREEK
0.1 MI E OF CLEMSONVILLE, Frederick, MD
Built 1998 Load: 99.9 t ADT: 322
WOODVILLE ROAD
FairOver: WOODVILLE BRANCH
0.1 MI N OF BOTTOM RD, Frederick, MD
Built 1972 Load: 99.9 t ADT: 1,333
GAMBRILL PARK ROAD
FairOver: LITTLE FISHING CREEK
N. OF MOUNTAINDALE ROAD, Frederick, MD
Built 1980 Load: 99.9 t ADT: 50
MOUNT PHILLIP ROAD
FairOver: BRANCH OF ROCK CREEK
230 S OF US ALT 40, Frederick, MD
Built 1980 Load: 99.9 t ADT: 5,847
Read our methodology - how this data is sourced, computed, and verified.
Related
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.