Total bridges
66
Public highway bridges in Mason County
County profile · official public datasets
Mason County, MI
66 public highway bridges tracked in the FHWA National Bridge Inventory: 39.4% rated Good, 53% Fair, 7.6% Poor.
- 66
- Public bridges
- 39.4%
- Good condition
- 7.6%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Mason County posts a better-than-median Poor-condition share among rated counties in the state across rated county bridge inventory.
- Top 35%
- lowest Poor share in state
- 7.6%
- Poor-condition share
- 66
- public highway bridges
- 1977
- 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.
Mason County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Mason County ranks #29 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7.6%). Mason County, Michigan contains 66 public highway bridges. Roughly 39.4% are rated “Good,” 53% “Fair,” and 7.6% “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
39.4%
26 of 66 rated 7-9
Fair condition
53%
35 of 66 rated 5-6
Poor condition
7.6%
5 of 66 rated 4 or below
In-state Poor-share rank
#29 of 83
Among Michigan counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 66 NBI-tracked bridges by lowest applicable component rating.
Good 39.4% (26)
Fair 53% (35)
Poor 7.6% (5)
Mason County's Poor-condition bridges carry 3,774 vehicle crossings a day
That is 2.5% of the county's reported daily bridge traffic on 7.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 755 crossings a day against 1,564 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 66 of 66 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
34.8% of Mason County's bridges have passed the 50-year mark
23 of the 66 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 39.4% 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 79.5% of the county's Poor-condition bridge traffic
LAKESHORE DRIVE over M BAYOU HAMLIN LAKE, built 1970, carries 3,000 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 5-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 3,774 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Mason County's bridges were built
66 bridges with a recorded construction year, grouped by decade
- 1900s 5
1900–1909
5 bridges
- 1920s 3
1920–1929
3 bridges
- 1930s 3
1930–1939
3 bridges
- 1950s 2
1950–1959
2 bridges
- 1960s
1960–1969
8 bridges
- 1970s
1970–1979
7 bridges
- 1980s
1980–1989
17 bridges
- 1990s 5
1990–1999
5 bridges
- 2000s 4
2000–2009
4 bridges
- 2010s
2010–2019
9 bridges
- 2020s 3
2020–2029
3 bridges
What this shows Construction peaked in the 1980s, when 17 of the county's bridges still in the inventory were built, which is 25.8% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1977) matches the Michigan average (1976).
How Mason County compares with Michigan's closest counties by inventory size
The 5 Michigan counties nearest Mason County in number of bridges, with their condition splits. Its 7.6% Poor share is the 3rd-lowest of these 6. Its average build year of 1977 against a peer-group mean of 1980 is in line with the group.
Showing the 5 closest of 82 Michigan counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Barry County | 69 | 26.1% | 49.3% | 24.6% | 1977 |
| Baraga County | 68 | 61.8% | 30.9% | 7.4% | 1988 |
| Mason County (this page) | 66 | 39.4% | 53% | 7.6% | 1977 |
| Newaygo County | 65 | 43.1% | 46.2% | 10.8% | 1979 |
| Ontonagon County | 64 | 37.5% | 46.9% | 15.6% | 1970 |
| Wexford County | 64 | 26.6% | 67.2% | 6.3% | 1986 |
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 Mason 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 Mason County, both outside Michigan so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MI (66 bridges here).
- Chugach County, AK · 66 bridges
- Inyo County, CA · 66 bridges
- Broomfield County, CO · 66 bridges
- Cook County, GA · 66 bridges
Similar average build year
Nearest mean year-built outside MI (1977 here).
- San Diego County, CA · avg 1977 · 1,632 bridges
- King County, WA · avg 1977 · 1,238 bridges
- Riverside County, CA · avg 1977 · 1,117 bridges
- Shelby County, TN · avg 1977 · 1,077 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (66)
OLD US-31
FairOver: DURHAM CREEK
0.9 MI N OF OCEANA COL, Mason, MI
Built 1925 Load: 24.5 t ADT: 8,600
QUARTERLINE ROAD
FairOver: BIG SAUBLE RIVER
1.6 MI N OF TOWN LINE RD, Mason, MI
Built 1966 Load: 26.9 t ADT: 2,000
US-31
FairOver: BIG SABLE RIVER
4.9 MI S OF MANISTEE COL, Mason, MI
Built 1959 Load: 29.5 t ADT: 6,578
M-116
FairOver: BIG SABLE RIVER
5.0 MI N OF LUDINGTON, Mason, MI
Built 1990 Load: 30.8 t ADT: 901
US-31 NB
FairOver: KIBBY CREEK
2.3 MI N OF COUNTY LINE, Mason, MI
Built 1986 Load: 32.4 t ADT: 4,256
US-31 SB
FairOver: KIBBY CREEK
2.3 MI N OF COUNTY LINE, Mason, MI
Built 1986 Load: 32.4 t ADT: 4,256
WALHALLA ROAD
FairOver: S BR PERE MARQUETTE RIVR
5.5 MI S OF US-10, Mason, MI
Built 1978 Load: 32.7 t ADT: 701
JEBAVY ROAD
FairOver: LINCOLN RIVER
2.0 MI N OF US-10, Mason, MI
Built 1988 Load: 32.7 t ADT: 6,000
LAKESHORE DRIVE
FairOver: BASS LAKE OUTLET
1 MI N OF OCEANA CO LINE, Mason, MI
Built 1900 Load: 35.3 t ADT: 1,000
FREESOIL ROAD
FairOver: BIG SAUBLE RIVER
4.1 MI E OF FREESOIL, Mason, MI
Built 1960 Load: 36.4 t ADT: 800
CUSTER RD
FairOver: N BR LINCOLN RIVER
0.25 MI N OF FOUNTAIN RD, Mason, MI
Built 1960 Load: 36.4 t ADT: 1,100
FOUNTAIN ROAD
FairOver: N BR LINCOLN RIVER
0.25 MI E OF CUSTER RD, Mason, MI
Built 1960 Load: 36.4 t ADT: 1,000
SCOTTVILLE ROAD
FairOver: SWAN CREEK
4.5 MI S OF SCOTTVILLE, Mason, MI
Built 1900 Load: 36.6 t ADT: 2,200
WALHALLA ROAD
FairOver: N BR PERE MARQUETTE RIVR
1.0 MI S OF US-10, Mason, MI
Built 1964 Load: 37.9 t ADT: 500
HAWLEY ROAD
FairOver: CARR CREEK
5 MI S 2 MI OF W BRANCH, Mason, MI
Built 1900 Load: 38.2 t ADT: 300
OLD US-31
FairOver: CSX RR
0.4 MI S OF US-10, Mason, MI
Built 1935 Load: 39.2 t ADT: 11,200
CUSTER ROAD
FairOver: BIG SAUBLE RIVER
1.0 MI N OF FREESOIL, Mason, MI
Built 1981 Load: 39.9 t ADT: 707
US-31 NB
FairOver: PERE MARQUETTE RIVER
3.6 MI SE OF LUDINGTON, Mason, MI
Built 1989 Load: 41.1 t ADT: 2,498
CONRAD RD
FairOver: US-31
3.4 MI E OF LUDINGTON, Mason, MI
Built 1987 Load: 41.5 t ADT: 420
MEISENHEIMER RD
FairOver: US-31
3.0 MI N OF COUNTY LINE, Mason, MI
Built 1986 Load: 41.8 t ADT: 1,500
LANDON ROAD
FairOver: N BR PERE MARQUETTE RIVR
0.8 MI SOUTH OF US-10, Mason, MI
Built 1979 Load: 41.8 t ADT: 400
US-31 SB
FairOver: PERE MARQUETTE RIVER
3.6 MI SE OF LUDINGTON, Mason, MI
Built 1989 Load: 42.1 t ADT: 2,498
US-31 SB
FairOver: CSX RR
3.1 MI E OF LUDINGTON, Mason, MI
Built 1988 Load: 42.1 t ADT: 2,498
ANTHONY ROAD
FairOver: S BR PERE MARQUETTE RIVR
7 MI S 2 MI OF W BRANCH, Mason, MI
Built 1990 Load: 43.6 t ADT: 250
US-10
FairOver: WELDON CREEK
6.3 MI E OF US-31, Mason, MI
Built 1938 Load: 43.7 t ADT: 5,307
US-31 NB
FairOver: OLD US-31
3.5 MI SE OF LUDINGTON, Mason, MI
Built 1986 Load: 44.1 t ADT: 4,256
US-31 SB
FairOver: OLD US-31
3.5 MI SE OF LUDINGTON, Mason, MI
Built 1986 Load: 44.7 t ADT: 4,256
US-31 BR
FairOver: US-31
2.2 MI N OF COUNTY LINE, Mason, MI
Built 1986 Load: 45.0 t ADT: 1,400
STEPHENS ROAD
FairOver: N BR LINCOLN RIVER
1 MI W 0.5 MI S FOUNTAIN, Mason, MI
Built 1977 Load: 45.7 t ADT: 120
US-31
FairOver: S BR LINCOLN RIVER
4.2 MI N OF US-10, Mason, MI
Built 1992 Load: 47.3 t ADT: 6,578
OLD US-31
FairOver: PERE MARQUETTE RIVER
2.3 MI S OF US-10, Mason, MI
Built 1924 Load: 50.2 t ADT: 6,828
M-116
FairOver: LINCOLN RIVER
0.6 MI N OF LUDINGTON, Mason, MI
Built 1934 Load: 50.5 t ADT: 4,764
US-31
FairOver: N BR LINCOLN RIVER
6.3 MI N OF US-10, Mason, MI
Built 1992 Load: 52.2 t ADT: 6,578
FIRST STREET
FairOver: BLACK RIVER
VILLAGE OF CUSTER, Mason, MI
Built 1998 Load: 56.7 t ADT: 312
US-31 NB
FairOver: US-10 & US-31
3 MI E OF LUDINGTON, Mason, MI
Built 1987 Load: 61.9 t ADT: 2,498
CHAUVEZ RD
GoodOver: US-31
3.6 MI S OF LUDINGTON, Mason, MI
Built 1986 Load: 27.9 t ADT: 1,500
SCOTTVILLE ROAD
GoodOver: PERE MARQUETTE RIVER
1.0 MI S OF SCOTTVILLE, Mason, MI
Built 2009 Load: 32.4 t ADT: 5,220
VICTORY CORNER RD
GoodOver: N BR LINCOLN RIVER
4 MI W 4.5 M N SCOTTVILLE, Mason, MI
Built 2000 Load: 33.7 t ADT: 300
LAKESHORE DRIVE
GoodOver: PUMPED STORAGE PENSTOCKS
4 MI S OF LUDINGTON, Mason, MI
Built 1970 Load: 34.5 t ADT: 1,400
LASALLE ROAD
GoodOver: BIG SAUBLE RIVER
10.5 MI N 1M W SCOTTVILLE, Mason, MI
Built 2010 Load: 35.0 t ADT: 320
LINCOLN ROAD
GoodOver: TRIB TO MIDDLE BAYOU
0.25 MI N OF DEWEY ROAD, Mason, MI
Built 2009 Load: 36.4 t ADT: 300
SCHOENHERR RD
GoodOver: BIG SABLE RIVER
1 MI N OF FREESOIL RD, Mason, MI
Built 1960 Load: 36.4 t ADT: 100
STEPHENS ROAD
GoodOver: BIG SABLE RIVER
1 MI E 1 MI N OF FREESOIL, Mason, MI
Built 2017 Load: 38.9 t ADT: 1,369
TUTTLE ROAD
GoodOver: N BR LINCOLN RIVER
3 MI W 0.5 MI N FOUNTAIN, Mason, MI
Built 2022 Load: 40.8 t ADT: 49
DARR ROAD
GoodOver: N BR LINCOLN RIVER
4 MI W OF FOUNTAIN, Mason, MI
Built 2018 Load: 45.0 t ADT: 10
DARR ROAD
GoodOver: BIG SABLE RIVER
11 MI N 1 MI E SCOTTVILLE, Mason, MI
Built 2011 Load: 46.3 t ADT: 155
CUSTER ROAD
GoodOver: PERE MARQUETTE RIVER
1.0 MI S OF CUSTER, Mason, MI
Built 1953 Load: 47.3 t ADT: 610
OLD US-31
GoodOver: PERE MARQUETTE RIVER
1.9 MI S OF US-10, Mason, MI
Built 1925 Load: 48.0 t ADT: 7,076
US-31 NB
GoodOver: CSX RR
3.1 MI E OF LUDINGTON, Mason, MI
Built 1988 Load: 48.6 t ADT: 2,498
DECKER ROAD
GoodOver: S BR LINCOLN RIVER
2.5 MI N 1 MI E OF CUSTER, Mason, MI
Built 2017 Load: 53.8 t ADT: 547
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.