Total bridges
334
Public highway bridges in Boone County
County profile · official public datasets
Boone County, MO
334 public highway bridges tracked in the FHWA National Bridge Inventory: 49.4% rated Good, 46.7% Fair, 3.9% Poor.
- 334
- Public bridges
- 49.4%
- Good condition
- 3.9%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Boone County pairs a top-10% lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.
- Top 10%
- lowest Poor share in state
- 3.9%
- Poor-condition share
- 334
- public highway bridges
- 1984
- 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.
Boone County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Boone County ranks #11 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.9%). Boone County, Missouri contains 334 public highway bridges. Roughly 49.4% are rated “Good,” 46.7% “Fair,” and 3.9% “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
49.4%
165 of 334 rated 7-9
Fair condition
46.7%
156 of 334 rated 5-6
Poor condition
3.9%
13 of 334 rated 4 or below
In-state Poor-share rank
#11 of 115
Among Missouri counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 334 NBI-tracked bridges by lowest applicable component rating.
Good 49.4% (165)
Fair 46.7% (156)
Poor 3.9% (13)
Boone County's Poor-condition bridges carry 53,532 vehicle crossings a day
That is 3% of the county's reported daily bridge traffic on 3.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 4,118 crossings a day against 4,748 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 334 of 334 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
26.3% of Boone County's bridges have passed the 50-year mark
88 of the 334 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 49.4% 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 42.6% of the county's Poor-condition bridge traffic
IS 70 E over PERCHE CR, built 1958, carries 22,820 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 13-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 53,532 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Boone County's bridges were built
334 bridges with a recorded construction year, grouped by decade
- 1920s 11
1920–1929
11 bridges
- 1930s 5
1930–1939
5 bridges
- 1940s 7
1940–1949
7 bridges
- 1950s 26
1950–1959
26 bridges
- 1960s 21
1960–1969
21 bridges
- 1970s 32
1970–1979
32 bridges
- 1980s
1980–1989
105 bridges
- 1990s 26
1990–1999
26 bridges
- 2000s
2000–2009
46 bridges
- 2010s
2010–2019
43 bridges
- 2020s 12
2020–2029
12 bridges
What this shows Construction peaked in the 1980s, when 105 of the county's bridges still in the inventory were built, which is 31.4% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1984, 5 years newer than the Missouri average of 1979.
How Boone County compares with Missouri's closest counties by inventory size
The 5 Missouri counties nearest Boone County in number of bridges, with their condition splits. Its 3.9% Poor share is the 1st-lowest of these 6. Its average build year of 1984 against a peer-group mean of 1983 is in line with the group.
Showing the 5 closest of 114 Missouri counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Boone County (this page) | 334 | 49.4% | 46.7% | 3.9% | 1984 |
| Franklin County | 331 | 38.7% | 56.8% | 4.5% | 1988 |
| Harrison County | 331 | 39.6% | 39% | 21.5% | 1981 |
| Bates County | 319 | 22.6% | 70.2% | 7.2% | 1977 |
| Audrain County | 314 | 41.4% | 53.8% | 4.8% | 1987 |
| Linn County | 313 | 39% | 43.5% | 17.6% | 1980 |
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 Boone 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 Boone County, both outside Missouri so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MO (334 bridges here).
- Dodge County, NE · 334 bridges
- Washoe County, NV · 334 bridges
- Shelby County, IL · 335 bridges
- Washington County, KS · 335 bridges
Similar average build year
Nearest mean year-built outside MO (1984 here).
- Hennepin County, MN · avg 1984 · 936 bridges
- Duval County, FL · avg 1984 · 831 bridges
- El Paso County, CO · avg 1984 · 686 bridges
- Bell County, TX · avg 1984 · 660 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Good-condition bridges (165)
MAGUIRE BLVD
GoodOver: N FK OF GRINDSTONE
S 20 T 48 N R 12 W, Boone, MO
Built 2009 Load: 61.2 t ADT: 2,925
BROADWAY ST
GoodOver: HINKSON CR
S 18 T 48 N R 12 W, Boone, MO
Built 2005 Load: 62.1 t ADT: 24,300
HIGH POINT LN
GoodOver: LIT BONNE FEMME CR
S 10 T 47 N R 13 W, Boone, MO
Built 2013 Load: 63.9 t ADT: 65
MEXICO GRAVEL RD
GoodOver: HOMINY BR
S 35 T 49 N R 12 W, Boone, MO
Built 2016 Load: 64.8 t ADT: 550
DRIPPING SPRING RD
GoodOver: SILVER FK CR
S 27 T 50 N R 13 W, Boone, MO
Built 2018 Load: 67.5 t ADT: 536
HARTSBURG BOTTOMRD
GoodOver: HART CR
S 18 T 45 N R 12 W, Boone, MO
Built 2021 Load: 68.4 t ADT: 113
RT WW E
GoodOver: S FK GRINDSTONE CR
S 22 T 48 N R 12 W, Boone, MO
Built 1993 Load: 72.9 t ADT: 6,622
SYCAMORE CREEK RD
GoodOver: TRIB TO PRAIRIE CR
S 2769 T 49 N R 14 W, Boone, MO
Built 2022 Load: 73.8 t ADT: 10
FOX HOLLOW RD
GoodOver: BR BONNE FEMME CR
S 12 T 46 N R 13 W, Boone, MO
Built 1998 Load: 95.4 t ADT: 50
MO 763 S
GoodOver: COW BRANCH
S 25 T 49 N R 13 W, Boone, MO
Built 2008 Load: 95.4 t ADT: 10,374
PEABODY RD
GoodOver: BR OF ROCKY FK
S 36 T 49 N R 12 W, Boone, MO
Built 1999 Load: 99.9 t ADT: 300
BROWN SCHOOL RD E
GoodOver: COW BRANCH
S 25 T 49 N R 13 W, Boone, MO
Built 2008 Load: 99.9 t ADT: 5,170
LOVERS LANE
GoodOver: SALING CR
S 7 T 51 N R 12 W, Boone, MO
Built 2012 Load: 99.9 t ADT: 10
OWENS SCHOOL RD
GoodOver: TRIB TO SILVER FK
S 16 T 50 N R 11 W, Boone, MO
Built 2012 Load: 99.9 t ADT: 30
CLELLIE HARMON RD
GoodOver: BASS CREEK
S 10 T 46 N R 12 W, Boone, MO
Built 2012 Load: 99.9 t ADT: 20
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.