Total bridges
52
Public highway bridges in Cass County
County profile · official public datasets
Cass County, MI
52 public highway bridges tracked in the FHWA National Bridge Inventory: 25% rated Good, 59.6% Fair, 15.4% Poor.
- 52
- Public bridges
- 25%
- Good condition
- 15.4%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Cass County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.
- 58th
- of 83 on Poor share
- 15.4%
- Poor-condition share
- 52
- public highway bridges
- 1970
- 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.
Cass County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Cass County ranks #58 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 15.4%). Cass County, Michigan contains 52 public highway bridges. Roughly 25% are rated “Good,” 59.6% “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.
Good condition
25%
13 of 52 rated 7-9
Fair condition
59.6%
31 of 52 rated 5-6
Poor condition
15.4%
8 of 52 rated 4 or below
In-state Poor-share rank
#58 of 83
Among Michigan counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 52 NBI-tracked bridges by lowest applicable component rating.
Good 25% (13)
Fair 59.6% (31)
Poor 15.4% (8)
Cass County's Poor-condition bridges carry 5,686 vehicle crossings a day
That is 4.7% 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 711 crossings a day against 1,662 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 52 of 52 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
55.8% of Cass County's bridges have passed the 50-year mark
29 of the 52 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 25% 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 45.6% of the county's Poor-condition bridge traffic
POKAGON RD over POKAGON CREEK, built 1960, carries 2,590 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 8-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 5,686 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Cass County's bridges were built
52 bridges with a recorded construction year, grouped by decade
- 1910s 2
1910–1919
2 bridges
- 1920s 2
1920–1929
2 bridges
- 1930s
1930–1939
5 bridges
- 1940s
1940–1949
5 bridges
- 1950s
1950–1959
7 bridges
- 1960s
1960–1969
5 bridges
- 1970s 3
1970–1979
3 bridges
- 1980s
1980–1989
9 bridges
- 1990s 3
1990–1999
3 bridges
- 2000s
2000–2009
5 bridges
- 2010s
2010–2019
4 bridges
- 2020s 2
2020–2029
2 bridges
What this shows Construction peaked in the 1980s, when 9 of the county's bridges still in the inventory were built, which is 17.3% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1970, 6 years older than the Michigan average of 1976.
How Cass County compares with Michigan's closest counties by inventory size
The 5 Michigan counties nearest Cass 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 1970 against a peer-group mean of 1967 is in line with the group.
Showing the 5 closest of 82 Michigan counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Crawford County | 54 | 14.8% | 66.7% | 18.5% | 1971 |
| Iron County | 54 | 20.4% | 59.3% | 20.4% | 1967 |
| Schoolcraft County | 54 | 27.8% | 66.7% | 5.6% | 1967 |
| Alger County | 53 | 30.2% | 58.5% | 11.3% | 1956 |
| Cass County (this page) | 52 | 25% | 59.6% | 15.4% | 1970 |
| Iosco County | 47 | 27.7% | 63.8% | 8.5% | 1972 |
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 Cass 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 Cass County, both outside Michigan so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MI (52 bridges here).
- Copper River County, AK · 52 bridges
- McDuffie County, GA · 52 bridges
- Terrell County, GA · 52 bridges
- Tensas County, LA · 52 bridges
Similar average build year
Nearest mean year-built outside MI (1970 here).
- Hamilton County, OH · avg 1970 · 783 bridges
- Yavapai County, AZ · avg 1970 · 543 bridges
- Garfield County, OK · avg 1970 · 504 bridges
- San Luis Obispo County, CA · avg 1970 · 401 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Good-condition bridges (13)
M-51
GoodOver: PEAVINE CREEK
4 MI S OF DOWAGIAC, Cass, MI
Built 2009 Load: 32.4 t ADT: 6,037
BURTON ROAD
GoodOver: MCKINZIE CREEK
HOWARD TWP SEC 7, Cass, MI
Built 1919 Load: 32.7 t ADT: 100
SINK ROAD
GoodOver: DOWAGIAC RIVER
5 MI N OF SUMNEVILLE, Cass, MI
Built 2019 Load: 41.1 t ADT: 413
MONETTE STREET
GoodOver: CHRISTIANA CREEK
3 MI E OF M-62, Cass, MI
Built 1993 Load: 44.9 t ADT: 3,400
WOOD ROAD
GoodOver: POKAGON CREEK
IN SUMNERVILLE, Cass, MI
Built 1988 Load: 45.4 t ADT: 82
US-12
GoodOver: VALLEY CREEK
0.3 MI E OF UNION, Cass, MI
Built 2011 Load: 46.7 t ADT: 7,350
LOWE STREET
GoodOver: DOWAGIAC CREEK
0.1 MI N OF JEFFERSON AVE, Cass, MI
Built 2003 Load: 51.5 t ADT: 709
MOUNT ZION STREET
GoodOver: CHRISTIANA CREEK
CALVIN TWP SEC 19, Cass, MI
Built 2017 Load: 52.5 t ADT: 232
IRR BIA RTE 1214
GoodOver: PEAVINE CREEK
EDWARDS STREET, Cass, MI
Built 2008 Load: 53.9 t ADT: 25
NORTHROP STREET
GoodOver: CHRISTIANA CREEK
0.25 MI E OF CHAIN LK ST, Cass, MI
Built 2008 Load: 61.2 t ADT: 143
OKEEFE ROAD
GoodOver: DOWAGIAC CREEK
4 MI N OF CASSOPOLIS, Cass, MI
Built 2021 Load: 65.1 t ADT: 495
REDFIELD STREET
GoodOver: CHRISTIANA CREEK
ONTWA TWP SEC 13/24, Cass, MI
Built 2012 Load: 65.4 t ADT: 2,555
RUDY ROAD
GoodOver: DOWAGIAC RIVER
1 MI E OF M-51, Cass, MI
Built 2022 Load: 75.5 t ADT: 70
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.