County profile · official public datasets

Ionia County, MI

119 public highway bridges tracked in the FHWA National Bridge Inventory: 32.8% rated Good, 58.8% Fair, 8.4% Poor.

119
Public bridges
32.8%
Good condition
8.4%
Poor condition

The verdict

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

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

Top 41%
lowest Poor share in state
8.4%
Poor-condition share
119
public highway bridges
1974
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.

Ionia County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Ionia County ranks #34 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.4%). Ionia County, Michigan contains 119 public highway bridges. Roughly 32.8% are rated “Good,” 58.8% “Fair,” and 8.4% “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

119

Public highway bridges in Ionia County

Good condition

32.8%

39 of 119 rated 7-9

Fair condition

58.8%

70 of 119 rated 5-6

Poor condition

8.4%

10 of 119 rated 4 or below

In-state Poor-share rank

#34 of 83

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

Condition distribution

Share of 119 NBI-tracked bridges by lowest applicable component rating.

Good
32.8% (39)
Fair
58.8% (70)
Poor
8.4% (10)

Ionia County's Poor-condition bridges carry 7,750 vehicle crossings a day

That is 1.6% of the county's reported daily bridge traffic on 8.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 775 crossings a day against 2,513 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 119 of 119 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

47.1% of Ionia County's bridges have passed the 50-year mark

56 of the 119 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 32.8% 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 32.7% of the county's Poor-condition bridge traffic

M-21 over MAPLE RIVER, built 1929, carries 2,533 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 10-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 7,750 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Ionia County's bridges were built

119 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1950s, when 26 of the county's bridges still in the inventory were built, which is 21.8% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year (1974) matches the Michigan average (1976).

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

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

The 5 Michigan counties nearest Ionia County in number of bridges, with their condition splits. Its 8.4% Poor share is the 3rd-lowest of these 6. Its average build year of 1974 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 Ionia County and the 5 Michigan counties closest to it in inventory size
County Bridges Poor
St. Joseph County 132 12.1%
Van Buren County 129 7%
Montcalm County 121 5%
Ionia County (this page) 119 8.4%
Branch County 118 21.2%
Chippewa County 112 12.5%

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

Similar inventory size

Nearest county inventories outside MI (119 bridges here).

Similar average build year

Nearest mean year-built outside MI (1974 here).

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

All 119 Good 39 Fair 70 Poor 10

All bridges (119)

I-96 EB

Fair

Over: CHARLOTTE HWY

S LTS OF PORTLAND, Ionia, MI

Built 1959 Load: 38.9 t ADT: 20,074

SOUTH BRIDGE ST S

Fair

Over: LAKE CREEK

IN SARANAC, Ionia, MI

Built 1987 Load: 38.9 t ADT: 1,333

SOUTH BRIDGE ST N

Fair

Over: LAKE CREEK

IN SARANAC, Ionia, MI

Built 1987 Load: 38.9 t ADT: 1,333

M-44 M-91

Fair

Over: MID MICH RR & FLAT RIVER

IN BELDING, Ionia, MI

Built 1950 Load: 39.5 t ADT: 9,043

I-96 EB

Fair

Over: GRAND RIVER & MARKET RD

0.2 MI W OF PORTLAND, Ionia, MI

Built 1959 Load: 40.2 t ADT: 14,899

I-96 WB

Fair

Over: GRAND RIVER AVE

E LTS OF PORTLAND, Ionia, MI

Built 1959 Load: 40.2 t ADT: 20,074

I-96 WB

Fair

Over: GRAND RIVER & MARKET RD

0.2 MI W OF PORTLAND, Ionia, MI

Built 1959 Load: 40.8 t ADT: 14,899

I-96 EB

Fair

Over: OKEMOS RD

S LTS OF PORTLAND, Ionia, MI

Built 1959 Load: 41.8 t ADT: 20,074

NICKLE PLATE RD

Fair

Over: MAPLE RIVER

2 MI N OF PEWAMO & 1 MI W, Ionia, MI

Built 1983 Load: 41.8 t ADT: 123

I-96 EB

Fair

Over: GRAND RIVER AVE

E LTS OF PORTLAND, Ionia, MI

Built 1959 Load: 42.4 t ADT: 20,074

GOODWIN ROAD

Fair

Over: LIBHART CREEK

2.0 MI E 3.0 MI S IONIA, Ionia, MI

Built 1982 Load: 43.4 t ADT: 112

WASHINGTON ROAD

Fair

Over: FISH CREEK

IN HUBBARDSTON, Ionia, MI

Built 1988 Load: 43.4 t ADT: 1,250

M-21

Fair

Over: RED CREEK

6.3 MI E OF KENT CO LINE, Ionia, MI

Built 1929 Load: 45.7 t ADT: 5,896

CHARLOTTE HIGHWAY

Fair

Over: GRAND RIVER

3 MI S VILL LIMITS PORT]D, Ionia, MI

Built 2001 Load: 45.7 t ADT: 510

DAVID HIGHWAY

Fair

Over: GRAND RIVER

4 MI N PORTLAND DAVID HWY, Ionia, MI

Built 1968 Load: 54.6 t ADT: 1,900

M-50

Fair

Over: TUPPER RIVER

0.5 MI NW OF BARRY COL, Ionia, MI

Built 1934 Load: 69.7 t ADT: 6,610

M-21

Fair

Over: SPIRES CREEK

0.3 MI W OF MUIR, Ionia, MI

Built 1932 Load: 79.7 t ADT: 5,580

I-96

Fair

Over: LIBHART CREEK

@ MILE POST 68.4, Ionia, MI

Built 1958 Load: 97.2 t ADT: 33,978

DAVID HIGHWAY

Fair

Over: CARBAUGH-E LIBBART DRAIN

SECTION 6 PORTLAND TWP, Ionia, MI

Built 1992 Load: 97.2 t ADT: 1,381

OLD M-91

Fair

Over: CONNORS POND SPLWY

S LTS OF BELDING, Ionia, MI

Built 1928 Load: 97.2 t ADT: 1,733

ELLISON ROAD

Good

Over: HOLMES & SPEARS DRAIN

0.25 MI W OF JOHNSON RD, Ionia, MI

Built 2014 Load: 16.8 t ADT: 250

BRIDGE ST

Good

Over: FLAT RIVER

IN BELDING, Ionia, MI

Built 2005 Load: 20.1 t ADT: 4,777

RUSSELL ROAD

Good

Over: TUPPER CREEK

0.25 MI E OF LAKE ODESSA, Ionia, MI

Built 1985 Load: 28.2 t ADT: 204

DIVISION STREET

Good

Over: LAKE CREEK

IN SARANAC, Ionia, MI

Built 1986 Load: 29.2 t ADT: 3,333

SUNFIELD HIGHWAY

Good

Over: LIBHART CREEK

2.5 MI S OF IONIA & 4MI E, Ionia, MI

Built 1986 Load: 31.8 t ADT: 134

WASHINGTON ROAD

Good

Over: FISH CREEK RACE

IN HUBBARDSTON, Ionia, MI

Built 1988 Load: 32.6 t ADT: 1,140

KEEFER HWY

Good

Over: SEBEWA CREEK

2 MI W OF PORTLAND 4 MI S, Ionia, MI

Built 1993 Load: 32.7 t ADT: 664

COWMAN ROAD

Good

Over: STOUGTON CREEK

0.25 MI W OF HUBBARDSTON, Ionia, MI

Built 1999 Load: 32.7 t ADT: 101

WAGAR ROAD

Good

Over: STONEY CREEK

1.5 MILES EAST OF MUIR, Ionia, MI

Built 1987 Load: 33.0 t ADT: 122

M-21

Good

Over: TOLES CREEK

2.6 MI E OF KENT CO LINE, Ionia, MI

Built 1929 Load: 35.6 t ADT: 5,100

M-66 NB

Good

Over: I-96

@ M-66, Ionia, MI

Built 1959 Load: 37.9 t ADT: 10,500

MAIN ST

Good

Over: FLAT RIVER

IN BELDING, Ionia, MI

Built 2014 Load: 38.6 t ADT: 748

CUTLER RD

Good

Over: I-96

2.9 MI NW OF CLINTON COL, Ionia, MI

Built 2019 Load: 39.9 t ADT: 830

CUTLER ROAD

Good

Over: LOOKING GLASS RIVER

2.0 MILES E OF PORTLAND, Ionia, MI

Built 2022 Load: 40.2 t ADT: 877

M-50

Good

Over: DUCK CREEK

3.5 MI E OF KENT CO, Ionia, MI

Built 2002 Load: 40.5 t ADT: 3,306

BIPPLEY ROAD

Good

Over: SEBEWA CREEK

0.75 MI N 0.25 MI W SEBEW, Ionia, MI

Built 2003 Load: 40.8 t ADT: 99

PORTLAND ROAD

Good

Over: MORRISON LAKE DRAIN

6.4 MI W OF M-66, Ionia, MI

Built 2011 Load: 41.8 t ADT: 904

PRAIRIE STREET

Good

Over: MAPLE RIVER

IN VILLAGE OF MUIR, Ionia, MI

Built 2015 Load: 43.4 t ADT: 600

LONG LAKE RD

Good

Over: FLAT RIVER

.8 MI EAST OF BELDING, Ionia, MI

Built 2014 Load: 44.1 t ADT: 1,367

W GRAND RIVER AVE

Good

Over: GRAND RIVER

100 FT WEST OF BUSINESS D, Ionia, MI

Built 1994 Load: 44.4 t ADT: 6,900

PRAIRIE CREEK ROAD

Good

Over: PRAIRIE CREEK

1.0 MILE EAST OF IONIA, Ionia, MI

Built 2004 Load: 45.7 t ADT: 490

BORDEN ROAD

Good

Over: STOUGHTON CREEK

2.25 MI W OF HUBBARDSTON, Ionia, MI

Built 2002 Load: 46.3 t ADT: 907

MACARTHUR ROAD

Good

Over: LAKE CREEK

1.0 MILE SOUTH OF SARANAC, Ionia, MI

Built 1997 Load: 46.3 t ADT: 250

WELCH ROAD

Good

Over: PRAIRIE CREEK

1.0 MI N 1.5 MI E IONIA, Ionia, MI

Built 1995 Load: 46.3 t ADT: 145

HASTINGS ROAD

Good

Over: DUCK CREEK

7.3 MI W VILL LAKE ODESSA, Ionia, MI

Built 2018 Load: 48.9 t ADT: 2,430

LONG LAKE ROAD

Good

Over: DICKERSON CREEK

3.25 MI NE INT M44 & M91, Ionia, MI

Built 2020 Load: 49.9 t ADT: 1,300

EAST MAIN STREET

Good

Over: PRAIRIE CREEK

1.0 MILE EAST OF IONIA, Ionia, MI

Built 1994 Load: 50.2 t ADT: 805

SUMMIT STREET

Good

Over: LAKE CREEK

IN SARANAC, Ionia, MI

Built 1995 Load: 54.1 t ADT: 777

HUBBARDSTON RD

Good

Over: MAPLE RIVER

3.5 MILES NORTH OF PEWAMO, Ionia, MI

Built 2000 Load: 57.3 t ADT: 1,170

DAVID HWY

Good

Over: LIBHART CREEK

2 MI S OF IONIA 4.6 MI E, Ionia, MI

Built 2016 Load: 57.7 t ADT: 1,550

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.