County profile · official public datasets

Saginaw County, MI

315 public highway bridges tracked in the FHWA National Bridge Inventory: 28.9% rated Good, 52.7% Fair, 18.4% Poor.

315
Public bridges: 28.9%
Good condition: 18.4%
Poor condition

The verdict

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

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

72nd
of 83 on Poor share: 18.4%
Poor-condition share: 315
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.

Saginaw County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Saginaw County ranks #72 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 18.4%). Saginaw County, Michigan contains 315 public highway bridges. Roughly 28.9% are rated “Good,” 52.7% “Fair,” and 18.4% “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

315

Public highway bridges in Saginaw County

Good condition

28.9%

91 of 315 rated 7-9

Fair condition

52.7%

166 of 315 rated 5-6

Poor condition

18.4%

58 of 315 rated 4 or below

In-state Poor-share rank

#72 of 83

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

Condition distribution

Share of 315 NBI-tracked bridges by lowest applicable component rating.

Good

28.9% (91)

Fair

52.7% (166)

Poor

18.4% (58)

Saginaw County's Poor-condition bridges carry 63,494 vehicle crossings a day

That is 3.8% of the county's reported daily bridge traffic on 18.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,114 crossings a day against 6,745 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 313 of 315 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

45.4% of Saginaw County's bridges have passed the 50-year mark

143 of the 315 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 28.9% 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 26.1% of the county's Poor-condition bridge traffic

GENESEE AVE over SAGINAW RIVER, built 1973, carries 16,546 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 58-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 63,494 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

1
1900s

1
1910s

5
1920s

10
1930s

11
1940s

6
1950s

26
1960s

27
1970s

75
1980s

36
1990s

41
2000s

37
2010s

34
2020s

5

What this shows Construction peaked in the 1970s, when 75 of the county's bridges still in the inventory were built, which is 23.8% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1979) matches the Michigan average (1976).

How Saginaw County compares with Michigan's closest counties by inventory size

The 5 Michigan counties nearest Saginaw County in number of bridges, with their condition splits. Its 18.4% Poor share is the 5th-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1976 is in line with the group.

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

Bridge inventory size and condition shares for Saginaw County and the 5 Michigan counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Genesee County	371	22.9%	61.7%	15.4%	1968
St. Clair County	327	41.3%	50.5%	8.3%	1985
Saginaw County (this page)	315	28.9%	52.7%	18.4%	1979
Monroe County	297	30%	54.5%	15.5%	1974
Berrien County	272	27.6%	66.5%	5.9%	1979
Washtenaw County	262	23.3%	56.5%	20.2%	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 Saginaw 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 Saginaw County, both outside Michigan so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside MI (315 bridges here).

Wyandotte County, KS · 315 bridges
Miami County, OH · 315 bridges
Monroe County, PA · 315 bridges
Buchanan County, IA · 316 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 315 Good 91 Fair 166 Poor 58

All bridges (315)

Sort:

Saginaw County Bridge Snapshot

Condition distribution

Saginaw County's Poor-condition bridges carry 63,494 vehicle crossings a day

45.4% of Saginaw County's bridges have passed the 50-year mark

One structure carries 26.1% of the county's Poor-condition bridge traffic

How Saginaw 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 (315)

TITTABAWASSEE RD

HESS RD

BIRCH RUN ROAD

M-58 EB TO I-675 E

I-75 SB

SHERIDAN ROAD

SCHROEDER ROAD

M-52

MERRILL ROAD

KRAMER ROAD

I-75 NB

TITTABAWASSEE ROAD

SHERIDAN ROAD

CHAPIN ROAD

DEHMEL ROAD

OUTER DRIVE

MICHIGAN RD

PEET ROAD

SHERIDAN ROAD

M-47 NB

M-47 SB

SHERIDAN ROAD

BRENNAN ROAD

M-52

DITCH ROAD

I-675 S RP TO I-75

I-75 SB

STATE ROAD

FREELAND ROAD

ROOSEVELT ROAD

BRENNAN ROAD

GLEANER ROAD

I-675 SB

I-675 SB

BRENNAN ROAD

HARRIS ROAD

VERNE ROAD

I-675 NB

I-675 NB

I-675 SB

WEST GARY ROAD

S FORDNEY ROAD

M-81

M-13

I-675 SB

I-675 S RP TO I-75

CANADA ROAD

I-675 NB

BUECHE ROAD

CHAPIN ROAD

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