Total bridges
108
Public highway bridges in Shelby County
County profile · official public datasets
Shelby County, MO
108 public highway bridges tracked in the FHWA National Bridge Inventory: 28.7% rated Good, 56.5% Fair, 14.8% Poor.
- 108
- Public bridges
- 28.7%
- Good condition
- 14.8%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Shelby County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- 95th
- of 115 on Poor share
- 14.8%
- Poor-condition share
- 108
- 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.
Shelby County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Shelby County ranks #95 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 14.8%). Shelby County, Missouri contains 108 public highway bridges. Roughly 28.7% are rated “Good,” 56.5% “Fair,” and 14.8% “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
28.7%
31 of 108 rated 7-9
Fair condition
56.5%
61 of 108 rated 5-6
Poor condition
14.8%
16 of 108 rated 4 or below
In-state Poor-share rank
#95 of 115
Among Missouri counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 108 NBI-tracked bridges by lowest applicable component rating.
Good 28.7% (31)
Fair 56.5% (61)
Poor 14.8% (16)
Shelby County's Poor-condition bridges carry 1,116 vehicle crossings a day
That is 2.2% of the county's reported daily bridge traffic on 14.8% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 70 crossings a day against 721 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 108 of 108 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
37% of Shelby County's bridges have passed the 50-year mark
40 of the 108 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 28.7% 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 26.9% of the county's Poor-condition bridge traffic
RT K E over BLACK CR, built 1952, carries 300 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 16-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 1,116 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Shelby County's bridges were built
108 bridges with a recorded construction year, grouped by decade
- 1900s 2
1900–1909
2 bridges
- 1910s 6
1910–1919
6 bridges
- 1920s 5
1920–1929
5 bridges
- 1930s
1930–1939
14 bridges
- 1940s 2
1940–1949
2 bridges
- 1950s 6
1950–1959
6 bridges
- 1960s 4
1960–1969
4 bridges
- 1970s 5
1970–1979
5 bridges
- 1980s 5
1980–1989
5 bridges
- 1990s
1990–1999
25 bridges
- 2000s
2000–2009
15 bridges
- 2010s
2010–2019
15 bridges
- 2020s 4
2020–2029
4 bridges
What this shows Construction peaked in the 1990s, when 25 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 25 to 34 years old in the 2024 inventory. Its average build year (1977) matches the Missouri average (1979).
How Shelby County compares with Missouri's closest counties by inventory size
The 5 Missouri counties nearest Shelby County in number of bridges, with their condition splits. Its 14.8% Poor share is the 5th-lowest of these 6. Its average build year of 1977 against a peer-group mean of 1970 is 7 years newer.
Showing the 5 closest of 114 Missouri counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Dallas County | 114 | 41.2% | 52.6% | 6.1% | 1973 |
| Cedar County | 112 | 24.1% | 50.9% | 25% | 1967 |
| Shelby County (this page) | 108 | 28.7% | 56.5% | 14.8% | 1977 |
| Morgan County | 105 | 28.6% | 61% | 10.5% | 1964 |
| Pulaski County | 104 | 21.2% | 68.3% | 10.6% | 1975 |
| Ste. Genevieve County | 104 | 38.5% | 51% | 10.6% | 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 Shelby 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 Shelby County, both outside Missouri so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MO (108 bridges here).
- Lassen County, CA · 108 bridges
- Pulaski County, IL · 108 bridges
- West Feliciana County, LA · 108 bridges
- Brown County, MN · 108 bridges
Similar average build year
Nearest mean year-built outside MO (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 (108)
COUNTY RD 345
PoorOver: SALT RVR
S 18 T 57 N R 10 W, Shelby, MO
Built 1920 Load: 7.2 t ADT: 50
COUNTY RD 478
PoorOver: BLACK CR
S 29 T 57 N R 9 W, Shelby, MO
Built 1910 Load: 8.1 t ADT: 35
COUNTY RD 256
PoorOver: BRANCH
S 33 T 59 N R 9 W, Shelby, MO
Built 1970 Load: 9.0 t ADT: 5
COUNTY RD 413
PoorOver: CREEK
S 5 T 56 N R 11 W, Shelby, MO
Built 1920 Load: 9.9 t ADT: 15
RT J E
PoorOver: TIGER FK
S 20 T 59 N R 9 W, Shelby, MO
Built 1956 Load: 11.7 t ADT: 190
RT K E
PoorOver: BLACK CR
S 19 T 58 N R 10 W, Shelby, MO
Built 1952 Load: 12.6 t ADT: 300
MO 151 S
PoorOver: SALT RVR
S 15 T 58 N R 12 W, Shelby, MO
Built 1948 Load: 13.5 t ADT: 291
COUNTY RD 177
PoorOver: S FABIUS RVR
S 11 T 59 N R 9 W, Shelby, MO
Built 1910 Load: 14.4 t ADT: 50
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.