County profile · official public datasets

Ingham County, MI

241 public highway bridges tracked in the FHWA National Bridge Inventory: 15.8% rated Good, 68.9% Fair, 15.4% Poor.

241
Public bridges
15.8%
Good condition
15.4%
Poor condition

The verdict

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

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

56th
of 83 on Poor share
15.4%
Poor-condition share
241
public highway bridges
1972
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.

Ingham County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Ingham County ranks #56 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 15.4%). Ingham County, Michigan contains 241 public highway bridges. Roughly 15.8% are rated “Good,” 68.9% “Fair,” and 15.4% “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

241

Public highway bridges in Ingham County

Good condition

15.8%

38 of 241 rated 7-9

Fair condition

68.9%

166 of 241 rated 5-6

Poor condition

15.4%

37 of 241 rated 4 or below

In-state Poor-share rank

#56 of 83

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

Condition distribution

Share of 241 NBI-tracked bridges by lowest applicable component rating.

Good
15.8% (38)
Fair
68.9% (166)
Poor
15.4% (37)

Ingham County's Poor-condition bridges carry 499,378 vehicle crossings a day

That is 13.5% of the county's reported daily bridge traffic on 15.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 13,497 crossings a day against 4,689 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 241 of 241 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

70.1% of Ingham County's bridges have passed the 50-year mark

169 of the 241 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 15.8% 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 7% of the county's Poor-condition bridge traffic

I-496 EB over RED CEDAR RIVER & RAMP V, built 1970, carries 34,831 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 37-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 499,378 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Ingham County's bridges were built

241 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1960s, when 99 of the county's bridges still in the inventory were built, which is 41.1% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1972) matches the Michigan average (1976).

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

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

The 5 Michigan counties nearest Ingham County in number of bridges, with their condition splits. Its 15.4% Poor share is the 4th-lowest of these 6. Its average build year of 1972 against a peer-group mean of 1978 is 6 years older.

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

Bridge inventory size and condition shares for Ingham County and the 5 Michigan counties closest to it in inventory size
County Bridges Poor
Washtenaw County 262 20.2%
Ottawa County 254 6.3%
Allegan County 244 16.8%
Tuscola County 242 5%
Ingham County (this page) 241 15.4%
Lenawee County 225 12.9%

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

Similar inventory size

Nearest county inventories outside MI (241 bridges here).

Similar average build year

Nearest mean year-built outside MI (1972 here).

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

All 241 Good 38 Fair 166 Poor 37

Poor-condition bridges (37)

DIETZ ROAD

Poor

Over: RED CEDAR RIVER

0.8 MILES N OF M-43, Ingham, MI

Built 1934 Load: 0.0 t ADT: 680

E ELM STREET

Poor

Over: RED CEDAR RIVER

IN THE CITY OF LANSING, Ingham, MI

Built 1980 Load: 2.3 t ADT: 2,000

DENNIS ROAD

Poor

Over: WEST CEDAR DRAIN

3.8 MI SE OF WEBBERVILLE, Ingham, MI

Built 1984 Load: 7.1 t ADT: 250

SMALL ACRES LANE

Poor

Over: PINE LAKE OUTLET DRAIN

1.3 MI NW OF OKEMOS, Ingham, MI

Built 1925 Load: 8.1 t ADT: 10

NOBLE ROAD

Poor

Over: DEER CREEK

2.1 MI SW OF WILLIAMSTON, Ingham, MI

Built 1925 Load: 13.0 t ADT: 490

M-43

Poor

Over: RED CEDAR RIVER

4.4 MI W OF WILLIAMSTON, Ingham, MI

Built 1924 Load: 15.6 t ADT: 13,900

FROST ROAD

Poor

Over: DEER CREEK

4.1 MI SW OF WILLIAMSTON, Ingham, MI

Built 1921 Load: 18.1 t ADT: 100

FARM LANE

Poor

Over: RED CEDAR RIVER

MICHIGAN STATE UNIVERSITY, Ingham, MI

Built 1926 Load: 18.1 t ADT: 11,510

HAGADORN ROAD

Poor

Over: MUD CREEK

2 MI N OF N LMTS OF E LAN, Ingham, MI

Built 1937 Load: 18.5 t ADT: 3,876

HOLT ROAD

Poor

Over: DOAN CREEK

4.6 MILES SE OF WILLIAMST, Ingham, MI

Built 1957 Load: 21.4 t ADT: 1,050

WALDO ROAD

Poor

Over: DEER CREEK DRAIN

4 MI NW OF DANSVILLE, Ingham, MI

Built 1967 Load: 22.0 t ADT: 320

CURTICE RD

Poor

Over: COLUMBIA CREEK

0.25 MI W OF GALE RD, Ingham, MI

Built 1969 Load: 24.0 t ADT: 200

W WALLACE STREET

Poor

Over: DEER CREEK

IN CITY OF WILLIAMSTON, Ingham, MI

Built 1945 Load: 24.6 t ADT: 10

GALE ROAD

Poor

Over: COLUMBIA CREEK

1 MI S & 7 MI W OF MASON, Ingham, MI

Built 1978 Load: 27.9 t ADT: 250

LINN ROAD

Poor

Over: DOAN CREEK

2.3 MI SE OF WILLIAMSTON, Ingham, MI

Built 1964 Load: 29.2 t ADT: 300

I-496 EB

Poor

Over: FOREST RD

IN LANSING (FOREST RD), Ingham, MI

Built 1963 Load: 30.8 t ADT: 29,013

M-36

Poor

Over: SYCAMORE CREEK

IN MASON (ASH ST), Ingham, MI

Built 1918 Load: 32.4 t ADT: 5,910

US-127 NB

Poor

Over: RED CEDAR RIV & RAMP V

IN EAST LANSING, Ingham, MI

Built 1964 Load: 32.7 t ADT: 24,173

RAMP T

Poor

Over: CSX RR & HOLMES ST

IN LANSING, Ingham, MI

Built 1969 Load: 33.7 t ADT: 7,766

I-96 WB

Poor

Over: M-99

@ M-99, Ingham, MI

Built 1962 Load: 34.7 t ADT: 21,057

I-496 EB

Poor

Over: RED CEDAR RIVER & RAMP V

W LTS OF E LANSING, Ingham, MI

Built 1970 Load: 35.3 t ADT: 34,831

I-496 EB

Poor

Over: CSX RR & TROWBRIDGE RMP

IN EAST LANSING, Ingham, MI

Built 1963 Load: 36.3 t ADT: 34,668

US-127 SB

Poor

Over: RED CEDAR RIV & RAMP V

IN EAST LANSING, Ingham, MI

Built 1964 Load: 36.9 t ADT: 24,173

I-96 WB

Poor

Over: WASHINGTON AVE

IN LANSING, Ingham, MI

Built 1962 Load: 37.3 t ADT: 22,051

I-496 WB

Poor

Over: US-127 SB

IN E LANSING, Ingham, MI

Built 1970 Load: 37.6 t ADT: 34,668

US-127 NB

Poor

Over: COLLEGE RD

0.7 MI S OF I-96, Ingham, MI

Built 1966 Load: 38.2 t ADT: 16,286

COLLEGE RD

Poor

Over: I-96

5.3 MI SE OF LANSING, Ingham, MI

Built 1963 Load: 39.2 t ADT: 5,200

HARRISON ROAD

Poor

Over: RED CEDAR RIVER

IN THE CITY OF E LANSING, Ingham, MI

Built 1937 Load: 40.1 t ADT: 18,646

EIFERT RD

Poor

Over: W AURELIUS DRAIN

0.3 MI S OF CURTICE RD, Ingham, MI

Built 1975 Load: 40.5 t ADT: 600

I-96 BL

Poor

Over: GTW SOUTH ST & RED CEDAR

IN LANSING (S CEDAR ST), Ingham, MI

Built 1952 Load: 43.4 t ADT: 23,865

I-496 WB

Poor

Over: RED CEDAR RIVER & RAMP V

W LTS OF E LANSING, Ingham, MI

Built 1970 Load: 44.1 t ADT: 34,831

I-96 EB

Poor

Over: DEER CREEK

0.4 MI W / WILLIAMSTON RD, Ingham, MI

Built 1962 Load: 44.4 t ADT: 23,287

I-96 WB

Poor

Over: DEER CREEK

0.4 MI W / WILLIAMSTON RD, Ingham, MI

Built 1962 Load: 44.7 t ADT: 23,287

I-496 WB RAMP

Poor

Over: CSX RR

IN EAST LANSING, Ingham, MI

Built 1963 Load: 47.6 t ADT: 2,802

I-496 EB

Poor

Over: GTW RR

IN EAST LANSING, Ingham, MI

Built 1963 Load: 53.1 t ADT: 34,668

I-496EB & US-127SB

Poor

Over: I-96 WB

I-96 & I-496/US127 INTRCH, Ingham, MI

Built 1966 Load: 53.5 t ADT: 29,356

AURELIUS ROAD

Poor

Over: PAWLOWSKI CREEK DRAIN

LANSING DELHI TWP S 2-3, Ingham, MI

Built 1978 Load: 60.9 t ADT: 13,294

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.