Total bridges
225
Public highway bridges in Lenawee County
County profile · official public datasets
Lenawee County, MI
225 public highway bridges tracked in the FHWA National Bridge Inventory: 47.6% rated Good, 39.6% Fair, 12.9% Poor.
- 225
- Public bridges
- 47.6%
- Good condition
- 12.9%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Lenawee 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.
- 50th
- of 83 on Poor share
- 12.9%
- Poor-condition share
- 225
- public highway bridges
- 1981
- 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.
Lenawee County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Lenawee County ranks #50 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 12.9%). Lenawee County, Michigan contains 225 public highway bridges. Roughly 47.6% are rated “Good,” 39.6% “Fair,” and 12.9% “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.
Good condition
47.6%
107 of 225 rated 7-9
Fair condition
39.6%
89 of 225 rated 5-6
Poor condition
12.9%
29 of 225 rated 4 or below
In-state Poor-share rank
#50 of 83
Among Michigan counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 225 NBI-tracked bridges by lowest applicable component rating.
Good 47.6% (107)
Fair 39.6% (89)
Poor 12.9% (29)
Lenawee County's Poor-condition bridges carry 63,116 vehicle crossings a day
That is 14% of the county's reported daily bridge traffic on 12.9% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 2,176 crossings a day against 1,047 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 225 of 225 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
29.8% of Lenawee County's bridges have passed the 50-year mark
67 of the 225 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 47.6% 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
US-223 over NORFOLK SOUTHERN RR, built 1941, carries 16,443 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 29-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 63,116 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Lenawee County's bridges were built
225 bridges with a recorded construction year, grouped by decade
- 1910s 3
1910–1919
3 bridges
- 1920s 3
1920–1929
3 bridges
- 1930s 4
1930–1939
4 bridges
- 1940s 8
1940–1949
8 bridges
- 1950s 15
1950–1959
15 bridges
- 1960s
1960–1969
23 bridges
- 1970s
1970–1979
34 bridges
- 1980s
1980–1989
52 bridges
- 1990s
1990–1999
40 bridges
- 2000s
2000–2009
32 bridges
- 2010s 8
2010–2019
8 bridges
- 2020s 3
2020–2029
3 bridges
What this shows Construction peaked in the 1980s, when 52 of the county's bridges still in the inventory were built, which is 23.1% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1981, 5 years newer than the Michigan average of 1976.
How Lenawee County compares with Michigan's closest counties by inventory size
The 5 Michigan counties nearest Lenawee County in number of bridges, with their condition splits. Its 12.9% Poor share is the 2nd-lowest of these 6. Its average build year of 1981 against a peer-group mean of 1975 is 6 years newer.
Showing the 5 closest of 82 Michigan counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Allegan County | 244 | 24.2% | 59% | 16.8% | 1978 |
| Tuscola County | 242 | 33.9% | 61.2% | 5% | 1980 |
| Ingham County | 241 | 15.8% | 68.9% | 15.4% | 1972 |
| Lenawee County (this page) | 225 | 47.6% | 39.6% | 12.9% | 1981 |
| Clinton County | 216 | 14.8% | 69.4% | 15.7% | 1975 |
| Calhoun County | 213 | 18.3% | 63.4% | 18.3% | 1971 |
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 Lenawee 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 Lenawee County, both outside Michigan so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MI (225 bridges here).
- Dallas County, AL · 225 bridges
- Madison County, IA · 225 bridges
- Mahaska County, IA · 225 bridges
- Lincoln County, KS · 225 bridges
Similar average build year
Nearest mean year-built outside MI (1981 here).
- Franklin County, OH · avg 1981 · 922 bridges
- Greenville County, SC · avg 1981 · 635 bridges
- Montgomery County, OH · avg 1981 · 632 bridges
- McLean County, IL · avg 1981 · 624 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (225)
SAND CREEK HWY
PoorOver: BLACK CREEK
0.3 MI NORTH OF WESTON RD, Lenawee, MI
Built 1963 Load: 14.3 t ADT: 544
RANGER HWY
PoorOver: LIME CRK
0.2 MI N OF RIDGEVILLE RD, Lenawee, MI
Built 1982 Load: 15.6 t ADT: 162
WOLF CREEK HWY
PoorOver: WOLF CREEK
SOUTH OF COUNTRY CLUB RD, Lenawee, MI
Built 1981 Load: 16.8 t ADT: 10,021
CARSON HWY
PoorOver: BEAVER CREEK
0.1 MI E OF BENT OAK HWY, Lenawee, MI
Built 1962 Load: 19.1 t ADT: 1,775
MORENCI ROAD
PoorOver: RANGER CREEK
0.5 MI EAST OF RANGER HWY, Lenawee, MI
Built 1950 Load: 19.6 t ADT: 1,698
SENECA HWY
PoorOver: RAISIN RIVER S BRANCH
0.2 MI S OF M-34, Lenawee, MI
Built 1978 Load: 19.8 t ADT: 340
HORTON RD
PoorOver: BLACK CREEK
0.5 MI W OF HODGES HWY, Lenawee, MI
Built 1993 Load: 22.0 t ADT: 148
HOAGLAND HWY
PoorOver: SWAMP RAISIN DRAIN
0.3 MI N OF LABERDEE RD, Lenawee, MI
Built 1910 Load: 22.9 t ADT: 45
CENTENNIAL RD
PoorOver: SCHROEDER BROOK DRAIN
0.1 MI W OF HOAGLAND HWY, Lenawee, MI
Built 1980 Load: 24.5 t ADT: 57
TREAT HWY
PoorOver: BLACK CREEK
0.4 MI S OF HORTON RD, Lenawee, MI
Built 1970 Load: 25.3 t ADT: 755
YANKEE RD
PoorOver: BEAR CREEK
0.3 MI WEST OF HODGES HWY, Lenawee, MI
Built 1978 Load: 26.2 t ADT: 94
PACKARD RD
PoorOver: BLACK CREEK
0.2 MI W OF MORSE HWY, Lenawee, MI
Built 1996 Load: 26.9 t ADT: 72
HOAGLAND HWY
PoorOver: MIDDLE BR OF MACON RIVER
0.3 MI S OF MILWAUKEE RD, Lenawee, MI
Built 1983 Load: 30.1 t ADT: 69
M-156
PoorOver: BEAR CREEK
2.7 MI S OF M-34, Lenawee, MI
Built 1925 Load: 30.8 t ADT: 1,791
M-34
PoorOver: S BR RAISIN RIVER
IN ADRIAN (BEECHER ST), Lenawee, MI
Built 1932 Load: 32.1 t ADT: 11,522
GORMAN RD
PoorOver: STONEY CREEK
0.07 MI W OF SAND CRK HWY, Lenawee, MI
Built 1978 Load: 33.4 t ADT: 906
DILLON HWY
PoorOver: BEAN CREEK
0.2 MI S OF LAWRENCE RD, Lenawee, MI
Built 1980 Load: 34.9 t ADT: 93
US-12
PoorOver: RIVER RAISIN
IN CLINTON, Lenawee, MI
Built 1977 Load: 36.9 t ADT: 10,834
HORTON RD
PoorOver: HAN DRAIN
0.3 MI W CROCKETT HWY, Lenawee, MI
Built 1988 Load: 37.3 t ADT: 352
BEECHER RD
PoorOver: SILVER CREEK
0.1 MI EAST OF US-127, Lenawee, MI
Built 1992 Load: 38.3 t ADT: 1,234
COOK ROAD
PoorOver: BIG MEADOW DRAIN
0.5 MI W OF ROBB HWY, Lenawee, MI
Built 1977 Load: 40.5 t ADT: 20
US-223
PoorOver: NORFOLK SOUTHERN RR
1.0 MI S OF ADRIAN, Lenawee, MI
Built 1941 Load: 48.3 t ADT: 16,443
GORMAN RD
PoorOver: BIG MEADOW DRAIN
0.1 MI E OF SCOTT HWY, Lenawee, MI
Built 1978 Load: 60.6 t ADT: 512
N UNION STREET
PoorOver: EVANS CREEK
283FT N OF CHIPPEWA ST, Lenawee, MI
Built 1934 Load: 63.5 t ADT: 2,657
LYONS HWY
PoorOver: NILE DRAIN
0.3 MI S OF MULBERRY RD, Lenawee, MI
Built 1977 Load: 94.9 t ADT: 507
Read our methodology - how this data is sourced, computed, and verified.
Related
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.