Total bridges
515
Public highway bridges in Montgomery County
County profile · official public datasets
Montgomery County, MD
515 public highway bridges tracked in the FHWA National Bridge Inventory: 38.8% rated Good, 56.3% Fair, 4.9% Poor.
- 515
- Public bridges
- 38.8%
- Good condition
- 4.9%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Montgomery County pairs a higher-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.
- 14th
- of 24 on Poor share
- 4.9%
- Poor-condition share
- 515
- public highway bridges
- 1978
- 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.
Montgomery County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Montgomery County ranks #14 of 24 Maryland counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.9%). Montgomery County, Maryland contains 515 public highway bridges. Roughly 38.8% are rated “Good,” 56.3% “Fair,” and 4.9% “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.
Good condition
38.8%
200 of 515 rated 7-9
Fair condition
56.3%
290 of 515 rated 5-6
Poor condition
4.9%
25 of 515 rated 4 or below
In-state Poor-share rank
#14 of 24
Among Maryland counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 515 NBI-tracked bridges by lowest applicable component rating.
Good 38.8% (200)
Fair 56.3% (290)
Poor 4.9% (25)
Montgomery County's Poor-condition bridges carry 242,194 vehicle crossings a day
That is 1.7% of the county's reported daily bridge traffic on 4.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 9,688 crossings a day against 21,166 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 513 of 515 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
44.9% of Montgomery County's bridges have passed the 50-year mark
231 of the 515 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 38.8% 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 16.5% of the county's Poor-condition bridge traffic
CLARA BARTON PARKW over CLARA BARTON PARKWAY (SB, built 1959, carries 40,057 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 25-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 242,194 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Montgomery County's bridges were built
515 bridges with a recorded construction year, grouped by decade
- pre-1900 1
Built before 1900
1 bridges
- 1910s 8
1910–1919
8 bridges
- 1920s 21
1920–1929
21 bridges
- 1930s 23
1930–1939
23 bridges
- 1940s 9
1940–1949
9 bridges
- 1950s
1950–1959
59 bridges
- 1960s
1960–1969
84 bridges
- 1970s
1970–1979
39 bridges
- 1980s
1980–1989
68 bridges
- 1990s
1990–1999
67 bridges
- 2000s
2000–2009
55 bridges
- 2010s
2010–2019
74 bridges
- 2020s 7
2020–2029
7 bridges
What this shows Construction peaked in the 1960s, when 84 of the county's bridges still in the inventory were built, which is 16.3% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1978, 6 years newer than the Maryland average of 1972.
How Montgomery County compares with Maryland's closest counties by inventory size
The 5 Maryland counties nearest Montgomery County in number of bridges, with their condition splits. Its 4.9% Poor share is the 4th-lowest of these 6. Its average build year of 1978 against a peer-group mean of 1974 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 (this page) | 515 | 38.8% | 56.3% | 4.9% | 1978 |
| Frederick County | 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 Montgomery 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 Montgomery County, both outside Maryland so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MD (515 bridges here).
- Queens County, NY · 514 bridges
- Grayson County, TX · 513 bridges
- Williamson County, TN · 520 bridges
- Douglas County, NE · 509 bridges
Similar average build year
Nearest mean year-built outside MD (1978 here).
- Orange County, CA · avg 1978 · 1,164 bridges
- Sumner County, KS · avg 1978 · 659 bridges
- Allen County, IN · avg 1978 · 613 bridges
- Livingston County, IL · avg 1978 · 579 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (290)
MD 28
FairOver: BRANCH OF ROCK CREEK
0.55 MILE EAST OF MD 911, Montgomery, MD
Built 1969 Load: 99.9 t ADT: 34,390
MD 586
FairOver: BRANCH OF ROCK CREEK
0.06 M E OF ANDREW STREET, Montgomery, MD
Built 1956 Load: 99.9 t ADT: 37,752
MD 124
FairOver: WHETSTONE RUN
0.447 M S of Midcounty, Montgomery, MD
Built 1986 Load: 99.9 t ADT: 23,621
MD 929A
FairOver: US 29 FUTURE RAMP E
0.033 MILE WEST OF US 29, Montgomery, MD
Built 2006 Load: 99.9 t ADT: 36,072
MUDDY BRANCH ROAD
FairOver: MUDDY BRANCH
1 MI N GREAT SENECA HWY, Montgomery, MD
Built 1987 Load: 99.9 t ADT: 24,785
MUDDY BRANCH ROAD
FairOver: SHADY BRANCH
0.5 MILES NORTH OF MD 28, Montgomery, MD
Built 1987 Load: 99.9 t ADT: 24,739
BRIGGS CHANEY ROAD
FairOver: PAINT BRANCH
2.4 MILES EAST OF MD 650, Montgomery, MD
Built 1974 Load: 99.9 t ADT: 20,551
BRIGGS CHANEY ROAD
FairOver: LITTLE PAINT BRANCH TRIB
1 MI EAST OF US 29, Montgomery, MD
Built 1994 Load: 99.9 t ADT: 12,450
HOWARD CHAPEL ROAD
FairOver: HAIGHTS BRANCH
1.7 MI NORTH OF MD 650, Montgomery, MD
Built 1963 Load: 99.9 t ADT: 580
HAWKINS CREAMERY R
FairOver: GREAT SENECA CREEK
1.3 MILES WEST OF MD 108, Montgomery, MD
Built 1961 Load: 99.9 t ADT: 550
DEMOCRACY BOULEVAR
FairOver: CABIN JOHN CREEK
.1 MI E OF SEVEN LOCKS RD, Montgomery, MD
Built 1967 Load: 99.9 t ADT: 31,775
TILDEN LANE
FairOver: OLD FARM CREEK
1.2 MILES WEST OF MD 187, Montgomery, MD
Built 1972 Load: 99.9 t ADT: 6,533
JONES MILL ROAD
FairOver: COQUELIN RUN
0.5 MILES NORTH OF MD 410, Montgomery, MD
Built 1949 Load: 99.9 t ADT: 7,542
MONTGOMERY VILLAGE
FairOver: CABIN BRANCH
2.2 MI N OF JCT SR MD 355, Montgomery, MD
Built 1972 Load: 99.9 t ADT: 31,900
RANDOLPH ROAD
FairOver: NORTHWEST BRANCH
0.1 MI E OF KEMP MILL RD, Montgomery, MD
Built 1976 Load: 99.9 t ADT: 60,342
DEMOCRACY BLVD
FairOver: BUCK BRANCH TRIBUTARY
1.5 MI E OF JCT SR MD 189, Montgomery, MD
Built 1989 Load: 99.9 t ADT: 16,800
GOLDLEAF DRIVE
FairOver: MINNEHAHA BRANCH
0.1 MI N OF JCT SR MD 614, Montgomery, MD
Built 1985 Load: 99.9 t ADT: 743
FATHER HURLEY BOUL
FairOver: TRIB TO LITTLE SENECA CR
0.3 MI SE OF JCT I-270, Montgomery, MD
Built 1995 Load: 99.9 t ADT: 44,490
LAURIE DRIVE
FairOver: HOLLYWOOD BRANCH
0.4 MI S JCT RANDLPH RD E, Montgomery, MD
Built 1965 Load: 99.9 t ADT: 575
SPARTAN ROAD
FairOver: TRIBUTARY TO JAMES CREEK
.1 MI N OF MD-108, Montgomery, MD
Built 1990 Load: 99.9 t ADT: 6,004
OLD BALTIMORE ROAD
FairOver: TRIBUTARY TO JAMES CREEK
0.5 MI N OF MD 108, Montgomery, MD
Built 1985 Load: 99.9 t ADT: 3,494
OLD BALTIMORE ROAD
FairOver: JAMES CREEK TRIBUTARY
1.2 MI. N. OF MD 108, Montgomery, MD
Built 1998 Load: 99.9 t ADT: 3,273
MONTROSE PARKWAY
FairOver: OLD FARM CREEK TRIBUTARY
1.0 MILE WEST OF I-270, Montgomery, MD
Built 2006 Load: 99.9 t ADT: 28,776
BEXHILL DRIVE
FairOver: SILVER CREEK
AT KENSINGTON PARKWAY, Montgomery, MD
Built 1985 Load: 99.9 t ADT: 1,029
CRYSTAL ROCK DRIVE
FairOver: TRIBUTARY TO LITTLE SENE
.6 M. N. OF MD. 27, Montgomery, MD
Built 1988 Load: 99.9 t ADT: 7,114
RICHTER FARM ROAD
FairOver: TRIB TO LITTLE SENECA CR
0.1 MILES SOUTH OF MD-117, Montgomery, MD
Built 2000 Load: 99.9 t ADT: 7,433
RUSSETT ROAD
FairOver: ROCK CREEK TRIBUTARY
0.65 MI SOUTH OF MD-28, Montgomery, MD
Built 1966 Load: 99.9 t ADT: 4,597
LOCBURY DRIVE
FairOver: TRIB TO LAKE CHURCHILL
0.5 MI. W. OF I-270, Montgomery, MD
Built 1992 Load: 99.9 t ADT: 105
HARVEST SQUARE COU
FairOver: BUCK BRANCH TRIB
1.8 MI. E. OF MD 190, Montgomery, MD
Built 1987 Load: 99.9 t ADT: 21
SEVEN LOCKS ROAD
FairOver: CABIN JOHN CREEK TRIBUTA
0.5 MI N. OF MD 191, Montgomery, MD
Built 1965 Load: 99.9 t ADT: 20,520
HATHAWAY DRIVE
FairOver: LUTES RUN
1300 FT. W. OF MD 182, Montgomery, MD
Built 1983 Load: 99.9 t ADT: 104
FOUNDERS MILL DRIV
FairOver: MILL CREEK TRIB
0.7 MI. S. OF MD 115, Montgomery, MD
Built 1983 Load: 99.9 t ADT: 105
LONG CORNER ROAD
FairOver: PATUXENT RIVER TRIB
1.90 MI. N. OF MD108, Montgomery, MD
Built 1970 Load: 99.9 t ADT: 821
BUREAU DRIVE
FairOver: LONG DRAUGHT BRANCH
0.4 MILES NORTH OF MD 117, Montgomery, MD
Built 1982 Load: 99.9 t ADT: 16,173
KENSINGTON PARKWAY
FairOver: SILVER CREEK
0.5 MI EAST OF MD 193, Montgomery, MD
Built 1940 Load: 99.9 t ADT: 4,601
BEACH DRIVE
FairOver: TRIB TO ROCK CREEK
0.9 MI SOUTH OF MD 547, Montgomery, MD
Built 1968 Load: 99.9 t ADT: 6,415
SLIGO CREEK PARKW
FairOver: TRIBUTARY TO SLIGO CREEK
0.9 MI SOUTH OF MD 320, Montgomery, MD
Built 1996 Load: 99.9 t ADT: 4,344
WOOTTON PARKWAY
FairOver: TRIBUTARY TO WATTS BRANC
0.8 MI W OF JCT SR 189, Montgomery, MD
Built 1971 Load: 99.9 t ADT: 14,464
CROFTON HILL LANE
FairOver: WATTS BRANCH TRIBUTARY
0.1 MILES SOUTH OF MD 28, Montgomery, MD
Built 1990 Load: 99.9 t ADT: 300
FALLSGROVE DRIVE
FairOver: TRIBUTARY TO WATTS BRANC
0.5M S OF MD 28, Montgomery, MD
Built 2003 Load: 99.9 t ADT: 5,725
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.