County profile · official public datasets

Coos County, NH

188 public highway bridges tracked in the FHWA National Bridge Inventory: 49.5% rated Good, 44.1% Fair, 6.4% Poor.

188
Public bridges: 49.5%
Good condition: 6.4%
Poor condition

The verdict

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

Coos County posts a better-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 40%
lowest Poor share in state: 6.4%
Poor-condition share: 188
public highway bridges: 1964
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.

Coos County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Coos County ranks #4 of 10 New Hampshire counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.4%). Coos County, New Hampshire contains 188 public highway bridges. Roughly 49.5% are rated “Good,” 44.1% “Fair,” and 6.4% “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

188

Public highway bridges in Coos County

Good condition

49.5%

93 of 188 rated 7-9

Fair condition

44.1%

83 of 188 rated 5-6

Poor condition

6.4%

12 of 188 rated 4 or below

In-state Poor-share rank

#4 of 10

Among New Hampshire counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 188 NBI-tracked bridges by lowest applicable component rating.

Good

49.5% (93)

Fair

44.1% (83)

Poor

6.4% (12)

Coos County's Poor-condition bridges carry 5,976 vehicle crossings a day

That is 2.1% of the county's reported daily bridge traffic on 6.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 498 crossings a day against 1,515 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 185 of 188 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

63.8% of Coos County's bridges have passed the 50-year mark

120 of the 188 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 49.5% 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 71.8% of the county's Poor-condition bridge traffic

US 2 over PEA BROOK, built 1932, carries 4,291 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 12-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 5,976 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

4
1900s

1
1910s

4
1920s

10
1930s

22
1940s

12
1950s

25
1960s

27
1970s

24
1980s

20
1990s

16
2000s

13
2010s

7
2020s

3

What this shows Construction peaked in the 1960s, when 27 of the county's bridges still in the inventory were built, which is 14.4% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1964) matches the New Hampshire average (1968).

How Coos County compares with New Hampshire's closest counties by inventory size

The 5 New Hampshire counties nearest Coos County in number of bridges, with their condition splits. Its 6.4% Poor share is the 4th-lowest of these 6. Its average build year of 1964 against a peer-group mean of 1966 is in line with the group.

Showing the 5 closest of 9 New Hampshire counties eligible for comparison.

Bridge inventory size and condition shares for Coos County and the 5 New Hampshire counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Carroll County	193	54.9%	40.9%	4.1%	1966
Cheshire County	192	41.7%	46.9%	11.5%	1960
Coos County (this page)	188	49.5%	44.1%	6.4%	1964
Sullivan County	158	45.6%	49.4%	5.1%	1963
Strafford County	136	63.2%	27.9%	8.8%	1971
Belknap County	112	58%	37.5%	4.5%	1969

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 Coos 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 Coos County, both outside New Hampshire so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside NH (188 bridges here).

Pope County, AR · 188 bridges
Kennebec County, ME · 188 bridges
Socorro County, NM · 188 bridges
Baker County, OR · 188 bridges

Similar average build year

Nearest mean year-built outside NH (1964 here).

Bergen County, NJ · avg 1964 · 577 bridges
Morris County, NJ · avg 1964 · 508 bridges
Baltimore city County, MD · avg 1964 · 374 bridges
Ross County, OH · avg 1964 · 356 bridges

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

All 188 Good 93 Fair 83 Poor 12

All bridges (188)

Sort:

Coos County Bridge Snapshot

Condition distribution

Coos County's Poor-condition bridges carry 5,976 vehicle crossings a day

63.8% of Coos County's bridges have passed the 50-year mark

One structure carries 71.8% of the county's Poor-condition bridge traffic

How Coos County compares with New Hampshire's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

All bridges (188)

AIRPORT ROAD

NH 26

US 2 US 3

US 3

NH145

CHRISTINE LAKE RD

VT114 MAIN STREET

BOG ROAD

GARLAND ROAD

CHRISTIE ROAD

NH145

NH135

NH115A

CEDAR STREAM ROAD

SPUR ROAD

US 3

NH 26

US 3

CASCADE STREET

WATER STREET

NH 16

BALSAMS BK DR PVT

US 3

US 2

US 3

OLD NH110

STEARNS BROOK ROAD

LEIGHTON MEADOW RD

CHICKWOLNEPY ROAD

MURPHY DAM ROAD

VILLAGE ROAD

OLD NH 16

US 2

FDR 12

NORTH ROAD

BOG ROAD

HILL ROAD

CARLETON HILL ROAD

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