County profile · official public datasets

Blair County, PA

338 public highway bridges tracked in the FHWA National Bridge Inventory: 39.1% rated Good, 50.9% Fair, 10.1% Poor.

338
Public bridges: 39.1%
Good condition: 10.1%
Poor condition

The verdict

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

Blair County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 40%
lowest Poor share in state: 10.1%
Poor-condition share: 338
public highway bridges: 1976
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.

Blair County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Blair County ranks #27 of 67 Pennsylvania counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 10.1%). Blair County, Pennsylvania contains 338 public highway bridges. Roughly 39.1% are rated “Good,” 50.9% “Fair,” and 10.1% “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

338

Public highway bridges in Blair County

Good condition

39.1%

132 of 338 rated 7-9

Fair condition

50.9%

172 of 338 rated 5-6

Poor condition

10.1%

34 of 338 rated 4 or below

In-state Poor-share rank

#27 of 67

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

Condition distribution

Share of 338 NBI-tracked bridges by lowest applicable component rating.

Good

39.1% (132)

Fair

50.9% (172)

Poor

10.1% (34)

Blair County's Poor-condition bridges carry 27,955 vehicle crossings a day

That is 1.9% of the county's reported daily bridge traffic on 10.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 822 crossings a day against 4,843 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 338 of 338 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

40.5% of Blair County's bridges have passed the 50-year mark

137 of the 338 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 39.1% 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 20.4% of the county's Poor-condition bridge traffic

25TH AVENUE over SPRING RUN, built 1961, carries 5,701 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 34-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 27,955 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

2
1900s

4
1910s

11
1920s

8
1930s

28
1940s

10
1950s

31
1960s

25
1970s

30
1980s

73
1990s

36
2000s

32
2010s

40
2020s

8

What this shows Construction peaked in the 1980s, when 73 of the county's bridges still in the inventory were built, which is 21.6% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1976, 6 years newer than the Pennsylvania average of 1970.

How Blair County compares with Pennsylvania's closest counties by inventory size

The 5 Pennsylvania counties nearest Blair County in number of bridges, with their condition splits. Its 10.1% Poor share is the 4th-lowest of these 6. Its average build year of 1976 against a peer-group mean of 1973 is in line with the group.

Showing the 5 closest of 66 Pennsylvania counties eligible for comparison.

Bridge inventory size and condition shares for Blair County and the 5 Pennsylvania counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Centre County	367	48%	46%	6%	1982
Lackawanna County	363	36.6%	45.7%	17.6%	1972
Northampton County	356	31.2%	59.6%	9.3%	1970
Cumberland County	348	39.1%	56%	4.9%	1975
Blair County (this page)	338	39.1%	50.9%	10.1%	1976
Monroe County	315	26.3%	52.7%	21%	1966

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

Similar inventory size

Nearest county inventories outside PA (338 bridges here).

Carter County, OK · 339 bridges
Placer County, CA · 337 bridges
Tama County, IA · 337 bridges
Cowley County, KS · 337 bridges

Similar average build year

Nearest mean year-built outside PA (1976 here).

Marion County, IN · avg 1976 · 958 bridges
Mohave County, AZ · avg 1976 · 641 bridges
Comanche County, OK · avg 1976 · 593 bridges
Prince George's County, MD · avg 1976 · 576 bridges

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

All 338 Good 132 Fair 172 Poor 34

All bridges (338)

Sort:

12TH STREET

Fair

Over: BALD EAGLE CREEK

BOROUGH OF TYRONE, Blair, PA

Built 1937 Load: 50.5 t ADT: 276

SR 4008

Fair

Over: GLENWHITE RUN

3.5 MI.W.OF ALTOONA, Blair, PA

Built 1932 Load: 51.7 t ADT: 1,527

24 1/2 STREET

Fair

Over: NORFOLK SOUTHERN RR

24 1/2 ST ALTOONA, Blair, PA

Built 1990 Load: 51.7 t ADT: 7,701

I-99 / US 220 NBL

Fair

Over: SR 1001/BUSINESS US 220

.5 MI.S.OF ALTOONA, Blair, PA

Built 1984 Load: 52.6 t ADT: 15,895

SR 4018

Fair

Over: RIGGLES GAP RUN

.5 MI.W.OF PINECROFT, Blair, PA

Built 1931 Load: 52.6 t ADT: 1,583

I-99 / US 220 SBL

Fair

Over: SR 1001/BUSINESS US 220

.5 MI.S.OF ALTOONA, Blair, PA

Built 1984 Load: 53.5 t ADT: 14,956

SR 1003

Fair

Over: BRUSH RUN

HOLLIDAYSBURG, Blair, PA

Built 1934 Load: 54.4 t ADT: 1,872

SR 1001 / BUS 220

Fair

Over: BRUSH RUN

VV BLVD @ 16TH ST-ALTOONA, Blair, PA

Built 1961 Load: 55.3 t ADT: 10,995

SR 4003

Fair

Over: MILL RUN

ALTOONA BEALE AV 31ST.ST., Blair, PA

Built 1958 Load: 56.2 t ADT: 8,187

SR 4019

Fair

Over: LITTLE JUNIATA RIVER

.25 MI.W.OF BELLWOOD, Blair, PA

Built 1966 Load: 56.2 t ADT: 2,035

29TH STREET

Fair

Over: NORFOLK SOUTHERN

29TH ST.@ BEALE AVENUE, Blair, PA

Built 1990 Load: 56.2 t ADT: 4,698

SR 4027/BUS US 220

Fair

Over: NORFOLK SOUTHERN RR

0.4 MILE SOUTH OF SR 4025, Blair, PA

Built 1939 Load: 57.2 t ADT: 6,463

SR 2014

Fair

Over: BEAVERDAM BR JUNIATA R.

HOLLIDAYSBURG, Blair, PA

Built 1953 Load: 58.1 t ADT: 3,468

SR 8004(22E > 99N)

Fair

Over: SR 1002

1 MI.W.OF HOLLIDAYSBURG, Blair, PA

Built 1984 Load: 58.1 t ADT: 8,985

SR 2013

Fair

Over: CLOVER CREEK

1.5 MI.E.OF WILLIAMSBURG, Blair, PA

Built 1956 Load: 63.5 t ADT: 861

T-414 Maple Hollow

Fair

Over: GILLANS RUN

MAPLE HOLLOW, Blair, PA

Built 1965 Load: 63.5 t ADT: 1,879

SR 4002

Fair

Over: SUGAR RUN

6 MI.W.OF ALTOONA, Blair, PA

Built 1932 Load: 65.3 t ADT: 1,407

SR 2008

Fair

Over: PLUM CREEK

1.5 MI.NE.ROARING SPRING, Blair, PA

Built 1940 Load: 67.1 t ADT: 474

SR 3005

Fair

Over: SMOKY RUN

.5 MI.S.OF KLAHR, Blair, PA

Built 1929 Load: 72.6 t ADT: 487

SR 1001/BUS US 220

Fair

Over: KETTLE CREEK

.25 MI.S.OF GREENWOOD, Blair, PA

Built 1961 Load: 75.3 t ADT: 12,875

SR 1013

Fair

Over: TR.SINKING RUN(DRY)

1.5 MI.NE.OF CULP, Blair, PA

Built 1930 Load: 88.9 t ADT: 530

T510 SCHOCH HOLLOW

Fair

Over: SCHELL RUN

.5 MI.W.OF TYRONE, Blair, PA

Blair County Bridge Snapshot

Condition distribution

Blair County's Poor-condition bridges carry 27,955 vehicle crossings a day

40.5% of Blair County's bridges have passed the 50-year mark

One structure carries 20.4% of the county's Poor-condition bridge traffic

How Blair County compares with Pennsylvania'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 (338)

12TH STREET

SR 4008

24 1/2 STREET

I-99 / US 220 NBL

SR 4018

I-99 / US 220 SBL

SR 1003

SR 1001 / BUS 220

SR 4003

SR 4019

29TH STREET

SR 4027/BUS US 220

SR 2014

SR 8004(22E > 99N)

SR 2013

T-414 Maple Hollow

SR 4002

SR 2008

SR 3005

SR 1001/BUS US 220

SR 1013

T510 SCHOCH HOLLOW

I-99 / US 220 NBL

I-99 / US 220 SBL

SR 1002

PA 164

PA 764

SR 4021

SR 4004

SR 4041

SR 3003

PA 36

I-99 / US 220 NBL

PA 865

SR 4027/BUS US 220

SR 4027

SR 4004

ALLEGHENY STREET

PARK AVENUE

ADAMS AVE

SR 4029

SR 3010

T606 Bald Eagle SP

T-353 Brumbaugh RD

SR 4027

I-99 / US 220 SBL

SR 4018

SR 1001/BUS US 220

SR 4018

SR 4027

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