County profile · official public datasets

St. Joseph County, MI

132 public highway bridges tracked in the FHWA National Bridge Inventory: 28.8% rated Good, 59.1% Fair, 12.1% Poor.

132
Public bridges: 28.8%
Good condition: 12.1%
Poor condition

The verdict

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

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

46th
of 83 on Poor share: 12.1%
Poor-condition share: 132
public highway bridges: 1979
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.

St. Joseph County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, St. Joseph County ranks #46 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 12.1%). St. Joseph County, Michigan contains 132 public highway bridges. Roughly 28.8% are rated “Good,” 59.1% “Fair,” and 12.1% “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

132

Public highway bridges in St. Joseph County

Good condition

28.8%

38 of 132 rated 7-9

Fair condition

59.1%

78 of 132 rated 5-6

Poor condition

12.1%

16 of 132 rated 4 or below

In-state Poor-share rank

#46 of 83

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

Condition distribution

Share of 132 NBI-tracked bridges by lowest applicable component rating.

Good

28.8% (38)

Fair

59.1% (78)

Poor

12.1% (16)

St. Joseph County's Poor-condition bridges carry 17,847 vehicle crossings a day

That is 8.1% of the county's reported daily bridge traffic on 12.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,115 crossings a day against 1,252 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 132 of 132 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

47.7% of St. Joseph County's bridges have passed the 50-year mark

63 of the 132 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 28.8% 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 25.8% of the county's Poor-condition bridge traffic

HOFFMAN STREET over ROCKEY RIVER, built 1960, carries 4,600 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 16-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 17,847 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

1
1900s

2
1920s

2
1930s

3
1940s

2
1950s

7
1960s

39
1970s

16
1980s

18
1990s

7
2000s

20
2010s

13
2020s

2

What this shows Construction peaked in the 1960s, when 39 of the county's bridges still in the inventory were built, which is 29.5% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1979) matches the Michigan average (1976).

How St. Joseph County compares with Michigan's closest counties by inventory size

The 5 Michigan counties nearest St. Joseph County in number of bridges, with their condition splits. Its 12.1% Poor share is the 4th-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1975 is in line with the group.

Showing the 5 closest of 82 Michigan counties eligible for comparison.

Bridge inventory size and condition shares for St. Joseph County and the 5 Michigan counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Muskegon County	144	20.1%	67.4%	12.5%	1968
Midland County	139	26.6%	56.1%	17.3%	1978
St. Joseph County (this page)	132	28.8%	59.1%	12.1%	1979
Van Buren County	129	32.6%	60.5%	7%	1976
Montcalm County	121	37.2%	57.9%	5%	1977
Ionia County	119	32.8%	58.8%	8.4%	1974

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 St. Joseph 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 St. Joseph County, both outside Michigan so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside MI (132 bridges here).

Kendall County, IL · 132 bridges
Massac County, IL · 132 bridges
Monroe County, IL · 132 bridges
Otero County, NM · 132 bridges

Similar average build year

Nearest mean year-built outside MI (1979 here).

Pima County, AZ · avg 1979 · 1,150 bridges
Jefferson County, KY · avg 1979 · 662 bridges
Spartanburg County, SC · avg 1979 · 638 bridges
McPherson County, KS · avg 1979 · 586 bridges

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

All 132 Good 38 Fair 78 Poor 16

All bridges (132)

Sort:

St. Joseph County Bridge Snapshot

Condition distribution

St. Joseph County's Poor-condition bridges carry 17,847 vehicle crossings a day

47.7% of St. Joseph County's bridges have passed the 50-year mark

One structure carries 25.8% of the county's Poor-condition bridge traffic

How St. Joseph County compares with Michigan'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 (132)

COVERED BRIDGE RD

E MAIN STREET

PEALER STREET

CROOKED CREEK ROAD

LAWRENCE RD

FIFTH AVENUE

M-86

STROBLE ROAD

MICHIGAN AVENUE

BENNETT ROAD

MINTDALE ROAD

US-131 SB

SCHWEITZER ROAD

QUAKER ROAD

CARLS ROAD

MCCLISH ROAD

WATER STEET

RAMBADT ROAD

DICKINSON ROAD

PEALER STREET

M-60 & US-131 BR

FLATBUSH ROAD

NULL ROAD

FAWN RIVER ROAD

PARKVILLE ROAD

M-60

M-60

CORRELL ROAD

CONSTANTINE STREET

SEVISON ROAD

KINGS MILL ROAD

FAWN RIVER ROAD

TOWNLINE ROAD

FULTON ROAD

DEAN STREET

BLOCK ROAD

HEIMBACH ROAD

NEEDHAM ROAD

STUBEY ROAD

ANGEVINE ROAD

WATTLES RD OLD M78

MIDDLE COLON ROAD

HAGELGANS ROAD

NOTTAWA ROAD

KINGS MILL ROAD

BROADWAY STREET

FILMORE ROAD

M-86 (S MAIN ST)

CLARK STREET

RAMBADT ROAD

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