County profile · official public datasets

Lehigh County, PA

381 public highway bridges tracked in the FHWA National Bridge Inventory: 29.4% rated Good, 59.3% Fair, 11.3% Poor.

381
Public bridges
29.4%
Good condition
11.3%
Poor condition

The verdict

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

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

Top 46%
lowest Poor share in state
11.3%
Poor-condition share
381
public highway bridges
1966
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.

Lehigh County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Lehigh County ranks #31 of 67 Pennsylvania counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 11.3%). Lehigh County, Pennsylvania contains 381 public highway bridges. Roughly 29.4% are rated “Good,” 59.3% “Fair,” and 11.3% “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

381

Public highway bridges in Lehigh County

Good condition

29.4%

112 of 381 rated 7-9

Fair condition

59.3%

226 of 381 rated 5-6

Poor condition

11.3%

43 of 381 rated 4 or below

In-state Poor-share rank

#31 of 67

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

Condition distribution

Share of 381 NBI-tracked bridges by lowest applicable component rating.

Good
29.4% (112)
Fair
59.3% (226)
Poor
11.3% (43)

Lehigh County's Poor-condition bridges carry 224,278 vehicle crossings a day

That is 4% of the county's reported daily bridge traffic on 11.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 5,216 crossings a day against 15,019 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 381 of 381 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

61.4% of Lehigh County's bridges have passed the 50-year mark

234 of the 381 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 29.4% 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 34% of the county's Poor-condition bridge traffic

US 22(LR 771) over TWP.RD.567* MICKLEY ROAD, built 1952, carries 76,351 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 43-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 224,278 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Lehigh County's bridges were built

381 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1950s, when 91 of the county's bridges still in the inventory were built, which is 23.9% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year (1966) matches the Pennsylvania average (1970).

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

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

The 5 Pennsylvania counties nearest Lehigh County in number of bridges, with their condition splits. Its 11.3% Poor share is the 3rd-lowest of these 6. Its average build year of 1966 against a peer-group mean of 1971 is 5 years older.

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

Bridge inventory size and condition shares for Lehigh County and the 5 Pennsylvania counties closest to it in inventory size
County Bridges Poor
Bradford County 399 10%
Delaware County 387 11.9%
Lehigh County (this page) 381 11.3%
Butler County 378 14.3%
Schuylkill County 368 26.6%
Centre County 367 6%

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

Similar inventory size

Nearest county inventories outside PA (381 bridges here).

Similar average build year

Nearest mean year-built outside PA (1966 here).

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

All 381 Good 112 Fair 226 Poor 43

Fair-condition bridges (226)

US 22(LR 771)

Fair

Over: LR 163* ROTH AVE.&19TH S

OVER 19TH ST./ ROTH AVE., Lehigh, PA

Built 1953 Load: 55.3 t ADT: 76,351

I-78(LR 1045)

Fair

Over: PA 100(LR 672)

FOGELSVILLE INTERCHANGE, Lehigh, PA

Built 1958 Load: 55.3 t ADT: 113,637

SR 4027 (LR 39060)

Fair

Over: JORDAN CREEK

GAME PRESERVE ROAD, Lehigh, PA

Built 1961 Load: 55.3 t ADT: 253

US 22 EB

Fair

Over: I 78 &T-572(TRI LEVEL)

FLYOVER I-78, Lehigh, PA

Built 1988 Load: 56.2 t ADT: 24,762

PA 100(LR 486)

Fair

Over: TRIB. SWOPE CREEK

MAIN STREET MACUNGIE, Lehigh, PA

Built 1960 Load: 56.2 t ADT: 12,643

PA 309(LR 163)

Fair

Over: JORDAN CREEK

GUTHSVILLE, Lehigh, PA

Built 1956 Load: 56.2 t ADT: 20,836

SR 1002 (LR 157)

Fair

Over: JORDAN CREEK & STREETS

TILGHMAN ST BRIDGE, Lehigh, PA

Built 1986 Load: 56.2 t ADT: 10,064

PA TPK (I-476)

Fair

Over: SR 0022 LR 771

LEHIGH VALLEY INTERCHANGE, Lehigh, PA

Built 1955 Load: 58.1 t ADT: 30,563

I-78 (LR 443)

Fair

Over: * SR3013 (LR 39082)

NEW SMITHVILLE, Lehigh, PA

Built 1958 Load: 59.0 t ADT: 35,420

SR 1007 (LR 153SP)

Fair

Over: CATASAUQUA CREEK

LEHIGH ST.CATASAUQUA, Lehigh, PA

Built 1913 Load: 59.0 t ADT: 5,758

SOUTH MAIN STREET

Fair

Over: MONOCACY CREEK

NORTH OF LEHIGH STREET, Lehigh, PA

Built 1966 Load: 60.8 t ADT: 1,000

SR 29(LR 557)

Fair

Over: LITTLE LEHIGH CREEK

AT INTERSECTION SR 2012, Lehigh, PA

Built 1958 Load: 65.3 t ADT: 19,257

LR 39088 SR 4001

Fair

Over: PA TPK (I-476)

WEST OF ALLENTOWN, Lehigh, PA

Built 1955 Load: 65.3 t ADT: 4,684

SR 4020 LR 39116

Fair

Over: PA TPK (I-476)

2 MI SOUTH OF SLATINGTON, Lehigh, PA

Built 1956 Load: 65.3 t ADT: 808

I-78(LR 1045)

Fair

Over: PA.TURNPIKE(I-476)NE EXT

OVER PA.TURNPIKE, Lehigh, PA

Built 1988 Load: 67.1 t ADT: 28,618

PA 309 NB (LR 781)

Fair

Over: SR 2023 (LR 39107)

PA.309NB OVER VERA CRUZ, Lehigh, PA

Built 1958 Load: 67.1 t ADT: 19,179

SR 4009 (LR 39057)

Fair

Over: JORDAN CREEK

MILL CK.&GAME PRESERVE RD, Lehigh, PA

Built 1876 Load: 68.0 t ADT: 667

PRESTON LANE

Fair

Over: SOUTH BR. SAUCON CREEK

NORTH OF CENTER VALLEY, Lehigh, PA

Built 1973 Load: 75.3 t ADT: 400

SR 78(LR 443)

Fair

Over: MILL CREEK *

NEW SMITHVILLE, Lehigh, PA

Built 1958 Load: 89.7 t ADT: 35,420

PA 100(LR 672)

Fair

Over: LYON CREEK

LYON VALLEY, Lehigh, PA

Built 1964 Load: 89.7 t ADT: 12,205

SR 4040 (LR 39072)

Fair

Over: TRIB. TO LYON CREEK

HOLBENS VALLEY RD., Lehigh, PA

Built 1930 Load: 89.7 t ADT: 1,946

SR 1002 (LR 443)

Fair

Over: PRIVATE RD.& L.CEDAR CK.

TILGHMAN W.OF CEDAR CREST, Lehigh, PA

Built 1936 Load: 92.5 t ADT: 21,937

SR 2044(LR 39002)

Fair

Over: TRIB. TO SAUCON CREEK

E.SAUCON VALLEY RD., Lehigh, PA

Built 1990 Load: 92.5 t ADT: 21,082

WILD CHERRY LANE

Fair

Over: LITTLE LEHIGH CREEK

NORTH OF MACUNGIE, Lehigh, PA

Built 1980 Load: 94.3 t ADT: 400

US 222

Fair

Over: IRON RUN

SR 222;RAMPS C&D, Lehigh, PA

Built 2005 Load: 97.1 t ADT: 40,766

SR145(LR555)

Fair

Over: COPLAY CREEK

1 MI.S.OF PA329, Lehigh, PA

Built 1941 Load: 99.8 t ADT: 17,057

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.