County profile · official public datasets

Lake County, IN

501 public highway bridges tracked in the FHWA National Bridge Inventory: 51.1% rated Good, 42.9% Fair, 6% Poor.

501
Public bridges: 51.1%
Good condition: 6%
Poor condition

The verdict

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

Lake 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.

61st
of 92 on Poor share: 6%
Poor-condition share: 501
public highway bridges: 1984
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.

Lake County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Lake County ranks #61 of 92 Indiana counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6%). Lake County, Indiana contains 501 public highway bridges. Roughly 51.1% are rated “Good,” 42.9% “Fair,” and 6% “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

501

Public highway bridges in Lake County

Good condition

51.1%

256 of 501 rated 7-9

Fair condition

42.9%

215 of 501 rated 5-6

Poor condition

30 of 501 rated 4 or below

In-state Poor-share rank

#61 of 92

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

Condition distribution

Share of 501 NBI-tracked bridges by lowest applicable component rating.

Good

51.1% (256)

Fair

42.9% (215)

Poor

6% (30)

Lake County's Poor-condition bridges carry 290,589 vehicle crossings a day

That is 3.2% of the county's reported daily bridge traffic on 5.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 10,378 crossings a day against 18,790 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 499 of 501 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

37.9% of Lake County's bridges have passed the 50-year mark

190 of the 501 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 51.1% 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 34.4% of the county's Poor-condition bridge traffic

I-80 EB over NS RR CN RR WYE, built 1953, carries 99,921 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 30-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 290,589 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

1
1900s

1
1920s

4
1930s

6
1940s

5
1950s

83
1960s

81
1970s

20
1980s

45
1990s

86
2000s

113
2010s

50
2020s

6

What this shows Construction peaked in the 2000s, when 113 of the county's bridges still in the inventory were built, which is 22.6% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year is 1984, 6 years newer than the Indiana average of 1978.

How Lake County compares with Indiana's closest counties by inventory size

The 5 Indiana counties nearest Lake County in number of bridges, with their condition splits. Its 6% Poor share is the 5th-lowest of these 6. Its average build year of 1984 against a peer-group mean of 1982 is in line with the group.

Showing the 5 closest of 91 Indiana counties eligible for comparison.

Bridge inventory size and condition shares for Lake County and the 5 Indiana counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Allen County	613	41.6%	51.5%	6.9%	1978
Lake County (this page)	501	51.1%	42.9%	6%	1984
Hamilton County	454	68.3%	29.1%	2.6%	1996
Gibson County	362	42.8%	53%	4.1%	1978
Hendricks County	355	41.4%	56.3%	2.3%	1982
Wayne County	343	41.1%	54.8%	4.1%	1975

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

Similar inventory size

Nearest county inventories outside IN (501 bridges here).

Cochise County, AZ · 501 bridges
Ventura County, CA · 501 bridges
Snohomish County, WA · 500 bridges
Garfield County, OK · 504 bridges

Similar average build year

Nearest mean year-built outside IN (1984 here).

Hennepin County, MN · avg 1984 · 936 bridges
Duval County, FL · avg 1984 · 831 bridges
El Paso County, CO · avg 1984 · 686 bridges
Bell County, TX · avg 1984 · 660 bridges

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

All 501 Good 256 Fair 215 Poor 30

All bridges (501)

Sort:

Lake County Bridge Snapshot

Condition distribution

Lake County's Poor-condition bridges carry 290,589 vehicle crossings a day

37.9% of Lake County's bridges have passed the 50-year mark

One structure carries 34.4% of the county's Poor-condition bridge traffic

How Lake County compares with Indiana'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 (501)

197TH AVENUE

US-12

US 30

US 41

SR 53

I-94 WB

I-80 WB WB RAMP

I-90 WB

SR 912 RAMP SSE

CLARK STREET

COLORADO STREET

BEVERLY LANE

191ST AVENUE

SR 55

SR 912 EB RMP TO I

I-80 W-SR 912W RAM

HARRISON STREET

SERENITY LANE

BLAINE ST.

I-65 NB

I-65 SB

US 6

CALUMET AVENUE

I-90 WB

SR 2

E 101ST AVE

COLFAX STREET

I-80 RAMP 2I

I-65 NB

I-65 SB

I-90 EB

125TH AVENUE

I-90 EB

MAIN STREET

MORSE STREET

4TH AVE

101ST AVENUE

SR 912 RAMP SSE

I-90 RAMP TO US-12

15TH AVENUE

68TH PLACE

I-80 EB

US 41

I-90 ON RAMP

SR 912 MARINA ACC

SR 912 MARINA ACC

SR 312

US 20

I-90 EB

I-90 EB

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