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.

Total bridges

309

Public highway bridges in Howard County

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

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.

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

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.

Bridge inventory size and condition shares for Howard County and the 5 Maryland counties closest to it in inventory size
County Bridges Poor
Anne Arundel County 389 1.5%
Baltimore city County 374 8.6%
Howard County (this page) 309 5.8%
Washington County 300 4.7%
Harford County 275 4.7%
Allegany County 245 6.1%

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).

Similar average build year

Nearest mean year-built outside MD (1978 here).

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

All 309 Good 111 Fair 180 Poor 18

Good-condition bridges (111)

MD 100

Good

Over: CSX RR OCONNOR ROAD

0.24 M W OF AA CO LINE, Howard, MD

Built 1996 Load: 49.9 t ADT: 83,402

MD 32 WB

Good

Over: US 1

1.50 MILES N OF AA CO, Howard, MD

Built 1983 Load: 50.3 t ADT: 80,612

KNIGHTS BRIDGE RD

Good

Over: HAMMONDS BRANCH

0.2 MI S OF GORMAN RD, Howard, MD

Built 1992 Load: 51.2 t ADT: 1,230

CEDAR LANE

Good

Over: MIDDLE PATUXENT RIVER

.02 Mi N of MD 32, Howard, MD

Built 1994 Load: 52.2 t ADT: 17,121

MD 100 EBR

Good

Over: US 29 NBR

0.24 MILE SOUTH OF MD 103, Howard, MD

Built 1992 Load: 52.6 t ADT: 75,332

MD 175 WBR

Good

Over: SNOWDEN RIVER PARKWAY

0.84 MILE WEST OF MD 108, Howard, MD

Built 2001 Load: 52.6 t ADT: 32,168

HAVILAND MILL ROAD

Good

Over: PATUXENT RIVER

1.5 MI E OF MD 650, Howard, MD

Built 1998 Load: 53.5 t ADT: 776

BETHANY LANE

Good

Over: LITTLE PATUXENT RIVER

0.1 MI N OF US RTE 40, Howard, MD

Built 2006 Load: 54.0 t ADT: 7,980

BROKEN LAND PKWY

Good

Over: US 29 RAMP D(1)

0.13 MI S OF US 29, Howard, MD

Built 1992 Load: 55.3 t ADT: 32,730

DORSEY RUN ROAD

Good

Over: DEEP RUN

0.5 MI SE OF US 1, Howard, MD

Built 1995 Load: 55.3 t ADT: 50

MD 175 EBR

Good

Over: SNOWDEN RIVER PARKWAY

0.84 MILE WEST OF MD 108, Howard, MD

Built 2001 Load: 55.8 t ADT: 30,855

MARRIOTTSVILLE ROA

Good

Over: LITTLE PATUXENT RIVER

0.23 MILE NORTH OF IS 70, Howard, MD

Built 1967 Load: 55.8 t ADT: 2,616

TRIADELPHIA ROAD

Good

Over: MIDDLE PATUXENT RIVER

1.2 MI S OF MD RTE 144, Howard, MD

Built 1986 Load: 56.7 t ADT: 2,474

DAISY ROAD

Good

Over: CATTAIL CREEK

0.5 MI N UNION CHAPEL RD, Howard, MD

Built 2017 Load: 57.1 t ADT: 1,679

MD 100

Good

Over: OLD MONT. RD & DEEP RUN

0.62 MILE WEST OF MD 103, Howard, MD

Built 1998 Load: 57.6 t ADT: 82,092

MD 100

Good

Over: DORSEY STATION ACCESS RD

0.39 M W OF AA CO LINE, Howard, MD

Built 1996 Load: 57.6 t ADT: 83,402

MD 100

Good

Over: DORSEY STATION ACCESS RD

0.39 M W OF AA CO LINE, Howard, MD

Built 1996 Load: 57.6 t ADT: 83,402

MD 100 EBR

Good

Over: US 29 RAMP 7

0.05 M N OF BR NO 1311900, Howard, MD

Built 1992 Load: 59.0 t ADT: 75,332

SHAKER DR

Good

Over: MD 32

0.75 MI N OF MD 732, Howard, MD

Built 1981 Load: 60.8 t ADT: 5,031

OLD MONTGOMERY RD

Good

Over: DEEP RUN

0.5 MI S OF MD RTE 103, Howard, MD

Built 2013 Load: 60.8 t ADT: 9,224

MD 32 WB

Good

Over: GUILFORD ROAD

1.0 MILE NORTH OF IS 95, Howard, MD

Built 1980 Load: 63.0 t ADT: 91,311

MD 100

Good

Over: OLD MONT. RD & DEEP RUN

0.62 MILE WEST OF MD 103, Howard, MD

Built 1998 Load: 63.5 t ADT: 82,092

MD 103

Good

Over: MD 100

1.35 MILE NORTH OF I-95, Howard, MD

Built 1997 Load: 63.9 t ADT: 12,911

MD 104

Good

Over: MD 100

0.12 MILE NORTH OF MD 108, Howard, MD

Built 1998 Load: 65.8 t ADT: 12,400

JOHN MCADAM DR

Good

Over: DORSEY BRANCH

800 FT S OF MD 175, Howard, MD

Built 2000 Load: 66.7 t ADT: 30

BONNIE BRANCH RD

Good

Over: BONNIE BRANCH

0.2 MI E OF COLLEGE AVE, Howard, MD

Built 2006 Load: 68.0 t ADT: 1,000

GUILFORD ROAD

Good

Over: CSX TRANSPORTATION

ON ANNE ARUNDEL CO LINE, Howard, MD

Built 2008 Load: 69.8 t ADT: 13,485

MD 32 EB

Good

Over: LITTLE PATUXENT RIVER

0.23 M S OF SHAKER DRIVE, Howard, MD

Built 1981 Load: 70.7 t ADT: 81,712

GREAT STAR DRIVE

Good

Over: CRICKETT CREEK

1.0 Mile SE of MD 108, Howard, MD

Built 1997 Load: 70.7 t ADT: 6,583

ELLICOTT CENTER DR

Good

Over: UNNAMED STREAM

400 FT NW OF ROGERS AVE, Howard, MD

Built 2003 Load: 71.2 t ADT: 1,814

RIVER ROAD

Good

Over: ROCKBURN BRANCH

AT ROCKBURN RD, Howard, MD

Built 2022 Load: 71.6 t ADT: 250

SHADY LANE

Good

Over: DORSEY BRANCH

0.5 MI N OF SHARP RD, Howard, MD

Built 2011 Load: 72.6 t ADT: 1,300

MD 32 EBR

Good

Over: MIDDLE PATUXENT RIVER

0.89 MILE NORTH OF US 29, Howard, MD

Built 1995 Load: 73.0 t ADT: 61,442

MD 97

Good

Over: PATUXENT RIVER

ON MONTGOMERY CO LINE, Howard, MD

Built 2000 Load: 73.5 t ADT: 13,200

MD 100J

Good

Over: MD 100

.11 M N OF MEADOWBROOK LA, Howard, MD

Built 1992 Load: 73.9 t ADT: 18,231

PARK CIRCLE DRIVE

Good

Over: DEEP RUN

0.4 MI N MD 176 HO/AA CO., Howard, MD

Built 1990 Load: 73.9 t ADT: 870

LARK BROWN ROAD

Good

Over: DORSEY RUN

0.04 MI W OF MD RTE 108, Howard, MD

Built 1991 Load: 76.6 t ADT: 6,274

HOMEWOOD ROAD

Good

Over: MIDDLE PATUXENT RIVER

1 MI W OF MD RTE 108, Howard, MD

Built 2000 Load: 76.6 t ADT: 5,182

ROXBURY ROAD

Good

Over: DORSEY BRANCH

0.5 MI E OF MD RTE 97, Howard, MD

Built 2002 Load: 77.1 t ADT: 1,079

MAXWELL COURT

Good

Over: UNNAMED STREAM

0.4 Mile West of MD 1, Howard, MD

Built 1995 Load: 78.9 t ADT: 50

Bellows Spring Ele

Good

Over: Deep Run Creek

BELLOW SPRING ELEM SCHOOL, Howard, MD

Built 2003 Load: 82.5 t ADT: 500

SHEPPARD LANE

Good

Over: MIDDLE PATUXENT RIVER

0.6 MI N OF MD RTE 108, Howard, MD

Built 1997 Load: 87.5 t ADT: 3,027

MD 32 Northbound

Good

Over: Terrapin Branch

0.82 MI. SOUTH OF MD 144, Howard, MD

Built 2020 Load: 93.0 t ADT: 29,475

MD 32 Southbound

Good

Over: Terrapin Branch

0.82 MI. SOUTH OF MD 144, Howard, MD

Built 2020 Load: 93.0 t ADT: 29,475

MD 32 Northbound

Good

Over: Middle Patuxent River

1.18 MILE SOUTH OF MD 144, Howard, MD

Built 2020 Load: 93.0 t ADT: 29,475

MD 32 Southbound

Good

Over: Middle Patuxent River

1.18 MILE SOUTH OF MD144A, Howard, MD

Built 2020 Load: 93.0 t ADT: 29,475

MD 100

Good

Over: TRIB TO RED HILL BRANCH

.25 M E OF LONG GATE PKWY, Howard, MD

Built 1993 Load: 99.9 t ADT: 80,680

MD 100

Good

Over: RED HILL BRANCH

0.6 M E OF LONG GATE PKWY, Howard, MD

Built 1993 Load: 99.9 t ADT: 80,680

MD 100M (COCA COLA

Good

Over: BRANCH OF DEEP RUN

0.06 M N OF AA CO LINE, Howard, MD

Built 1998 Load: 99.9 t ADT: 13,792

HIPSLEY MILL ROAD

Good

Over: CABIN BRANCH

0.4 MI E OF ELLICOTT ROAD, Howard, MD

Built 2003 Load: 99.9 t ADT: 421

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.