County profile · official public datasets

Penobscot County, ME

301 public highway bridges tracked in the FHWA National Bridge Inventory: 20.9% rated Good, 61.1% Fair, 17.9% Poor.

301
Public bridges: 20.9%
Good condition: 17.9%
Poor condition

The verdict

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

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

10th
of 16 on Poor share: 17.9%
Poor-condition share: 301
public highway bridges: 1972
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.

Penobscot County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Penobscot County ranks #10 of 16 Maine counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 17.9%). Penobscot County, Maine contains 301 public highway bridges. Roughly 20.9% are rated “Good,” 61.1% “Fair,” and 17.9% “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.

Total bridges

301

Public highway bridges in Penobscot County

Good condition

20.9%

63 of 301 rated 7-9

Fair condition

61.1%

184 of 301 rated 5-6

Poor condition

17.9%

54 of 301 rated 4 or below

In-state Poor-share rank

#10 of 16

Among Maine counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 301 NBI-tracked bridges by lowest applicable component rating.

Good

20.9% (63)

Fair

61.1% (184)

Poor

17.9% (54)

Penobscot County's Poor-condition bridges carry 216,009 vehicle crossings a day

That is 17.6% of the county's reported daily bridge traffic on 17.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 4,000 crossings a day against 4,879 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 301 of 301 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

58.5% of Penobscot County's bridges have passed the 50-year mark

176 of the 301 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 20.9% 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 11.7% of the county's Poor-condition bridge traffic

I 95 over ROUTE 15 (BROADWAY), built 1960, carries 25,340 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 54-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 216,009 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

1
1900s

2
1910s

1
1920s

9
1930s

27
1940s

21
1950s

29
1960s

77
1970s

23
1980s

23
1990s

21
2000s

27
2010s

24
2020s

16

What this shows Construction peaked in the 1960s, when 77 of the county's bridges still in the inventory were built, which is 25.6% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1972) matches the Maine average (1970).

How Penobscot County compares with Maine's closest counties by inventory size

The 5 Maine counties nearest Penobscot County in number of bridges, with their condition splits. Its 17.9% Poor share is the 6th-lowest of these 6. Its average build year of 1972 against a peer-group mean of 1971 is in line with the group.

Showing the 5 closest of 15 Maine counties eligible for comparison.

Bridge inventory size and condition shares for Penobscot County and the 5 Maine counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Cumberland County	344	26.5%	61.6%	11.9%	1974
Penobscot County (this page)	301	20.9%	61.1%	17.9%	1972
Oxford County	252	25%	57.5%	17.5%	1968
York County	236	32.6%	58.1%	9.3%	1976
Aroostook County	229	17.9%	71.6%	10.5%	1970
Kennebec County	188	19.1%	67.6%	13.3%	1965

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 Penobscot 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 Penobscot County, both outside Maine so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside ME (301 bridges here).

Madison County, IN · 301 bridges
Cedar County, IA · 301 bridges
Crawford County, IA · 301 bridges
Harrison County, MS · 301 bridges

Similar average build year

Nearest mean year-built outside ME (1972 here).

Santa Clara County, CA · avg 1972 · 964 bridges
Madison County, AL · avg 1972 · 710 bridges
Kern County, CA · avg 1972 · 668 bridges
York County, PA · avg 1972 · 569 bridges

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

All 301 Good 63 Fair 184 Poor 54

All bridges (301)

Sort:

Penobscot County Bridge Snapshot

Condition distribution

Penobscot County's Poor-condition bridges carry 216,009 vehicle crossings a day

58.5% of Penobscot County's bridges have passed the 50-year mark

One structure carries 11.7% of the county's Poor-condition bridge traffic

How Penobscot County compares with Maine'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 (301)

RIVER RD

MOODYS MILLS RD

I 95 NB

COUNTY RD

MILLS RD

PENOB RIVER BR

I 95 NB

N HOWLAND RD

I 95 SB

I 95 SB

IRR BIA RTE 201

GILMAN FALLS AV

GRIFFIN RD

I 95 NB

I 395 EB

SILVER MILLS RD

I 95 SB

I 95

US 202

ALTON TANNERY RD

RIDGE RD

SHIN POND RD

I 95 SB

HUDSON RD

HOLTS MILLS RD

MILL CREEK RD

ONE ST

MOOSEHEAD TRL

MAIN RD

MEDWAY RD

N HOWLAND RD

ARGYLE RD

MOOSEHEAD TRL

I 95 SB

LOUD RD

PEA RIDGE RD

COLDBROOK RD

I 95 SB

I 95 NB

MEDWAY RD

SEBOEIS RD

INDEPENDENT ST

SECOND ST

FRANKLIN ST

FROST ST

FRANKLIN ST

I 95 NB

COUNTY RD

MAIN ST

RAMP OFF TO STILLW

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