Total bridges
309
Public highway bridges in Howard County
County profile · official public datasets
Howard County, MD
309 public highway bridges tracked in the FHWA National Bridge Inventory: 35.9% rated Good, 58.3% Fair, 5.8% Poor.
- 309
- Public bridges
- 35.9%
- Good condition
- 5.8%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Howard 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.
- 16th
- of 24 on Poor share
- 5.8%
- Poor-condition share
- 309
- 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.
Howard County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Howard County ranks #16 of 24 Maryland counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.8%). Howard County, Maryland contains 309 public highway bridges. Roughly 35.9% are rated “Good,” 58.3% “Fair,” and 5.8% “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
35.9%
111 of 309 rated 7-9
Fair condition
58.3%
180 of 309 rated 5-6
Poor condition
5.8%
18 of 309 rated 4 or below
In-state Poor-share rank
#16 of 24
Among Maryland counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 309 NBI-tracked bridges by lowest applicable component rating.
Good 35.9% (111)
Fair 58.3% (180)
Poor 5.8% (18)
Howard County's Poor-condition bridges carry 46,181 vehicle crossings a day
That is 0.5% of the county's reported daily bridge traffic on 5.8% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 2,566 crossings a day against 20,094 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 308 of 309 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
46.9% of Howard County's bridges have passed the 50-year mark
145 of the 309 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 35.9% 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 23.7% of the county's Poor-condition bridge traffic
TAMAR DRIVE over UNNAMED STREAM, built 1970, carries 10,941 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 18-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 46,181 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Howard County's bridges were built
309 bridges with a recorded construction year, grouped by decade
- 1900s 2
1900–1909
2 bridges
- 1910s 1
1910–1919
1 bridges
- 1920s 10
1920–1929
10 bridges
- 1930s 10
1930–1939
10 bridges
- 1940s 8
1940–1949
8 bridges
- 1950s 13
1950–1959
13 bridges
- 1960s
1960–1969
34 bridges
- 1970s
1970–1979
81 bridges
- 1980s
1980–1989
40 bridges
- 1990s
1990–1999
59 bridges
- 2000s
2000–2009
34 bridges
- 2010s 8
2010–2019
8 bridges
- 2020s 9
2020–2029
9 bridges
What this shows Construction peaked in the 1970s, when 81 of the county's bridges still in the inventory were built, which is 26.2% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1978, 6 years newer than the Maryland average of 1972.
How Howard County compares with Maryland's closest counties by inventory size
The 5 Maryland counties nearest Howard County in number of bridges, with their condition splits. Its 5.8% Poor share is the 4th-lowest of these 6. Its average build year of 1978 against a peer-group mean of 1969 is 9 years newer.
Showing the 5 closest of 23 Maryland counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Anne Arundel County | 389 | 32.6% | 65.8% | 1.5% | 1980 |
| Baltimore city County | 374 | 16% | 75.4% | 8.6% | 1964 |
| Howard County (this page) | 309 | 35.9% | 58.3% | 5.8% | 1978 |
| Washington County | 300 | 28.3% | 67% | 4.7% | 1956 |
| Harford County | 275 | 38.2% | 57.1% | 4.7% | 1973 |
| Allegany County | 245 | 36.7% | 57.1% | 6.1% | 1971 |
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 Howard 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 Howard County, both outside Maryland so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MD (309 bridges here).
- Mississippi County, AR · 309 bridges
- Athens County, OH · 309 bridges
- Washington County, OH · 309 bridges
- Franklin County, IL · 310 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 (180)
IS 95 SB
FairOver: MIDDLE PATUXENT RIVER
0.18 MILE NORTH OF IS 95I, Howard, MD
Built 1970 Load: 49.0 t ADT: 186,750
US 1 NB
FairOver: LITTLE PATUXENT RIVER
0.38 MILE SOUTH OF MD 32, Howard, MD
Built 1955 Load: 49.4 t ADT: 19,773
MD 108 EB
FairOver: US 29
0.36 MILE WEST OF MD 108H, Howard, MD
Built 1986 Load: 49.4 t ADT: 19,880
US 29 SB
FairOver: LITTLE PATUXENT RIVER
1.62 MILES S OF MD 175, Howard, MD
Built 1950 Load: 49.9 t ADT: 73,292
TOWN & COUNTRY BOU
FairOver: SUCKER BRANCH
0.05 MI OF RODGERS AVE, Howard, MD
Built 1966 Load: 49.9 t ADT: 10,030
US 29 NB
FairOver: IS 70 RAMP G(7)
0.68 MILE SOUTH OF MD 99, Howard, MD
Built 1966 Load: 50.3 t ADT: 21,083
MD 32 EB
FairOver: US 29
3.22 MILES NORTH OF IS 95, Howard, MD
Built 1980 Load: 50.3 t ADT: 61,442
MD 32 WB
FairOver: US 29
3.22 MILES NORTH OF IS 95, Howard, MD
Built 1980 Load: 50.3 t ADT: 61,442
MD 32 EB
FairOver: US 1
1.50 MILES N OF AA CO, Howard, MD
Built 1983 Load: 50.3 t ADT: 80,612
US 29 NB
FairOver: US 29 RAMP A (07)
0.29 MILE SOUTH OF US 40, Howard, MD
Built 1966 Load: 50.8 t ADT: 130,203
IS 70 EB
FairOver: TRANS CONT PIPE LINE
0.35 MILE EAST OF US 40, Howard, MD
Built 1968 Load: 50.8 t ADT: 67,990
IS 95 NB
FairOver: GUILFORD ROAD
1.55 MILES N OF IS 95I, Howard, MD
Built 1970 Load: 50.8 t ADT: 187,920
MAYFIELD AVENUE
FairOver: DEEP RUN
0.2 MI W OF MD RTE 103, Howard, MD
Built 1945 Load: 52.2 t ADT: 5,788
MD 32 RAMP 9
FairOver: US 1
1.50 MILES N OF AA CO, Howard, MD
Built 1983 Load: 53.1 t ADT: 15,788
MD 32 RAMP 10
FairOver: US 1
1.50 MILES N OF AA CO, Howard, MD
Built 1983 Load: 53.1 t ADT: 9,852
WATERSVILLE ROAD
FairOver: HAY MEADOW BRANCH
1 MI N OLD FREDERICK RD, Howard, MD
Built 1935 Load: 53.1 t ADT: 539
IS 70 WB
FairOver: TRANS CONT PIPE LINE
0.35 MILE EAST OF US 40, Howard, MD
Built 1968 Load: 53.5 t ADT: 67,990
US 40
FairOver: Little Patuxent River
0.49 M W OF DOGWOOD DRIVE, Howard, MD
Built 1939 Load: 54.0 t ADT: 50,111
MD 175
FairOver: CSX RR
ON ANNE ARUNDEL CO LINE, Howard, MD
Built 1942 Load: 54.4 t ADT: 19,272
DORSEY RUN ROAD
FairOver: DORSEY RUN
0.5 MI S OF MD RTE 175, Howard, MD
Built 1955 Load: 57.1 t ADT: 6,745
BROKEN LAND PKWY
FairOver: US 29
1.79 MI S OF MD 175, Howard, MD
Built 1991 Load: 57.6 t ADT: 32,730
MD 100 WB
FairOver: IS 95
0.79 MILE WEST OF US 1, Howard, MD
Built 1970 Load: 59.0 t ADT: 90,902
MD 175 NB
FairOver: CO RTES 2035 & 2036
0.5 MILE NORTH OF MD 108, Howard, MD
Built 1975 Load: 59.0 t ADT: 30,855
MD 175 SB
FairOver: CO RTES 2035 & 2036
0.5 MILE NORTH OF MD 108, Howard, MD
Built 1975 Load: 59.4 t ADT: 34,795
IS 95 NB
FairOver: MD 32 EBR
0.28 M S OF GUILFORD ROAD, Howard, MD
Built 1970 Load: 59.9 t ADT: 187,920
US 1
FairOver: CSX TRANS.
0.85 MILE NORTH OF MD 32, Howard, MD
Built 1969 Load: 59.9 t ADT: 21,992
CRADLEROCK WAY
FairOver: UNNAMED STREAM
0.4 MI E BROKENLAND PKWY, Howard, MD
Built 1972 Load: 59.9 t ADT: 8,471
MD 108 EB
FairOver: LITTLE PATUXENT RIVER
0.55 MILE WEST OF US 29, Howard, MD
Built 1975 Load: 60.3 t ADT: 36,160
MD 108 WB
FairOver: LITTLE PATUXENT RIVER
0.55 MILE WEST OF US 29, Howard, MD
Built 1975 Load: 60.3 t ADT: 36,160
FOLLY QUARTER ROAD
FairOver: TRIBUTARY TO MIDDLE PATU
1.2 MI S OF MD RTE 144, Howard, MD
Built 1970 Load: 60.3 t ADT: 3,489
MD 100 EB
FairOver: IS 95
0.79 MILE WEST OF US 1, Howard, MD
Built 1970 Load: 61.2 t ADT: 90,902
ATHOL AVENUE
FairOver: UNNAMED STREAM
0.3 MI E OF LOUDON AVE, Howard, MD
Built 1945 Load: 62.1 t ADT: 680
MD 32 EB
FairOver: GUILFORD ROAD
1.0 MILE NORTH OF IS 95, Howard, MD
Built 1980 Load: 63.0 t ADT: 91,311
SENECA DRIVE
FairOver: US 29 AND RAMP I(7)
0.65 MILE NORTH OF MD 32, Howard, MD
Built 1993 Load: 63.0 t ADT: 5,031
LAKESIDE DRIVE
FairOver: TRIB. TO PATUXENT RIVER
0.2 MI W OF NICHOLS DRIV, Howard, MD
Built 1988 Load: 63.5 t ADT: 340
MD 100 RAMP A
FairOver: IS 95
0.79 MILE WEST OF US 1, Howard, MD
Built 1970 Load: 65.3 t ADT: 15,864
GORMAN ROAD
FairOver: IS 95
0.96 MI N OF MD 216, Howard, MD
Built 1970 Load: 65.3 t ADT: 8,371
OLD ANNAPOLIS ROAD
FairOver: LITTLE PATUXENT RIVER
0.04 MI W CO 76 & MD 108, Howard, MD
Built 1987 Load: 65.3 t ADT: 7,285
VOLLMERHAUSEN RD
FairOver: IS 95 SBR
2.2 MI N OF MD 216, Howard, MD
Built 1970 Load: 67.1 t ADT: 2,667
MD 94
FairOver: IS 70
0.40 MILE N OF MD 144A, Howard, MD
Built 1974 Load: 67.1 t ADT: 7,450
MULLINIX MILL ROAD
FairOver: PATUXENT RIVER
1.2 MI W OF MD 94, Howard, MD
Built 1991 Load: 67.1 t ADT: 383
IS 95 NB
FairOver: STANSFIELD RD
0.50 MI N OF PG CO, Howard, MD
Built 1970 Load: 67.6 t ADT: 186,040
MD 144A
FairOver: BR OF MIDDLE PATUXENT RI
1.5 MILES WEST OF US 32, Howard, MD
Built 1982 Load: 68.9 t ADT: 3,451
MD 32 WB
FairOver: LITTLE PATUXENT RIVER
0.23 M S OF SHAKER DRIVE, Howard, MD
Built 1981 Load: 70.7 t ADT: 81,712
US 29
FairOver: HAMMOND BRANCH
0.73 MILE NORTH OF MD 216, Howard, MD
Built 1951 Load: 72.6 t ADT: 69,132
MD 175 EB
FairOver: IS 95
0.49 MILE NORTH OF US 1, Howard, MD
Built 1970 Load: 73.9 t ADT: 33,570
MD 103
FairOver: US 29
1.89 MILES NORTH OF US 29, Howard, MD
Built 1992 Load: 77.1 t ADT: 12,161
LOUDON AVENUE
FairOver: UNNAMED STREAM
1.5 MI EAST OF RTE 1, Howard, MD
Built 2004 Load: 79.4 t ADT: 540
RIDINGS WAY
FairOver: UNNAMED STREAM
0.4 Mile West of MD 1, Howard, MD
Built 1996 Load: 79.4 t ADT: 100
MD 175 WB
FairOver: IS 95
0.49 MILE NORTH OF US 1, Howard, MD
Built 1970 Load: 79.8 t ADT: 28,774
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.