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)
DARR ROAD
GoodOver: S BR LINCOLN RIVER
4 MI N 1 MI E SCOTTVILLE, Mason, MI
Built 2018 Load: 53.8 t ADT: 167
CHAUVEZ ROAD
GoodOver: SWAN CREEK
4.5 MI EAST OF US-31, Mason, MI
Built 2014 Load: 56.4 t ADT: 1,913
REEK ROAD
GoodOver: N BR PERE MARQUETTE RIV
2 MI E 1.5 MI S OF CUSTER, Mason, MI
Built 2004 Load: 58.6 t ADT: 300
WASHINGTON AVE
GoodOver: PERE MARQUETTE LK BAYOU
IN LUDINGTON, Mason, MI
Built 2013 Load: 62.5 t ADT: 6,340
HAWLEY ROAD
GoodOver: S BR PERE MARQUETTE RIVR
5 MI S 2 MI OF W BRANCH, Mason, MI
Built 2019 Load: 63.2 t ADT: 150
FISHER ROAD
GoodOver: LINCOLN RIVER
4.5MI W 3 MI N SCOTTVILLE, Mason, MI
Built 2023 Load: 76.5 t ADT: 400
FOUNTAIN RD
GoodOver: N BR LINCOLN RIVER
1.25 MI E OF US-31, Mason, MI
Built 2022 Load: 81.0 t ADT: 1,050
AMBER ROAD
GoodOver: S BR LINCOLN RIVER
2 MI W 4 MI N SCOTTVILLE, Mason, MI
Built 1978 Load: 83.3 t ADT: 120
VICTORY CORNER
GoodOver: S BR LINCOLN RIVER
4 MI W 3 MI N SCOTTVILLE, Mason, MI
Built 1978 Load: 97.2 t ADT: 250
US-31 NB
GoodOver: QUINN CREEK
0.9 MI N OF COUNTY LINE, Mason, MI
Built 1986 Load: 99.9 t ADT: 4,256
US-31 SB
GoodOver: QUINN CREEK
0.9 MI N OF COUNTY LINE, Mason, MI
Built 1986 Load: 99.9 t ADT: 4,256
YOUNKERS ROAD
PoorOver: BIG SAUBLE RIVER
2.4 MI S OF FREESOIL ROAD, Mason, MI
Built 1960 Load: 5.2 t ADT: 49
CLEVELAND ST
PoorOver: N BR LINCOLN RIVER
0.1 MI S OF MAIN ST, Mason, MI
Built 1960 Load: 7.1 t ADT: 425
WILSON ROAD
PoorOver: S BR PERE MARQUETTE RIVR
2.5 MI S 2 MI E OF CUSTER, Mason, MI
Built 1900 Load: 21.1 t ADT: 100
LAKESHORE DRIVE
PoorOver: M BAYOU HAMLIN LAKE
5 MI N OF LUDINGTON, Mason, MI
Built 1970 Load: 24.0 t ADT: 3,000
TYNDALL ROAD
PoorOver: BIG SABLE RIVER
7 MI E OF FOUNTAIN, Mason, MI
Built 1900 Load: 26.6 t ADT: 200
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.