Total bridges
137
Public highway bridges in Mercer County
County profile · official public datasets
Mercer County, MO
137 public highway bridges tracked in the FHWA National Bridge Inventory: 44.5% rated Good, 36.5% Fair, 19% Poor.
- 137
- Public bridges
- 44.5%
- Good condition
- 19%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Mercer County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- 107th
- of 115 on Poor share
- 19%
- Poor-condition share
- 137
- public highway bridges
- 1976
- 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.
Mercer County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Mercer County ranks #107 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 19%). Mercer County, Missouri contains 137 public highway bridges. Roughly 44.5% are rated “Good,” 36.5% “Fair,” and 19% “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
44.5%
61 of 137 rated 7-9
Fair condition
36.5%
50 of 137 rated 5-6
Poor condition
19%
26 of 137 rated 4 or below
In-state Poor-share rank
#107 of 115
Among Missouri counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 137 NBI-tracked bridges by lowest applicable component rating.
Good 44.5% (61)
Fair 36.5% (50)
Poor 19% (26)
Mercer County's Poor-condition bridges carry 3,420 vehicle crossings a day
That is 13% of the county's reported daily bridge traffic on 19% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 132 crossings a day against 75 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 137 of 137 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
40.9% of Mercer County's bridges have passed the 50-year mark
56 of the 137 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 44.5% 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 55.1% of the county's Poor-condition bridge traffic
US 136 E over GRAND RVR OVRFL, built 1971, carries 1,883 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 26-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 3,420 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Mercer County's bridges were built
137 bridges with a recorded construction year, grouped by decade
- 1900s 8
1900–1909
8 bridges
- 1910s 3
1910–1919
3 bridges
- 1920s 4
1920–1929
4 bridges
- 1930s
1930–1939
14 bridges
- 1940s 6
1940–1949
6 bridges
- 1950s 11
1950–1959
11 bridges
- 1960s 4
1960–1969
4 bridges
- 1970s 7
1970–1979
7 bridges
- 1980s 3
1980–1989
3 bridges
- 1990s
1990–1999
30 bridges
- 2000s
2000–2009
31 bridges
- 2010s
2010–2019
13 bridges
- 2020s 3
2020–2029
3 bridges
What this shows Construction peaked in the 2000s, when 31 of the county's bridges still in the inventory were built, which is 22.6% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year (1976) matches the Missouri average (1979).
How Mercer County compares with Missouri's closest counties by inventory size
The 5 Missouri counties nearest Mercer County in number of bridges, with their condition splits. Its 19% Poor share is the 4th-lowest of these 6. Its average build year of 1976 against a peer-group mean of 1973 is in line with the group.
Showing the 5 closest of 114 Missouri counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Miller County | 142 | 40.1% | 49.3% | 10.6% | 1971 |
| St. Clair County | 139 | 25.2% | 55.4% | 19.4% | 1972 |
| Ralls County | 138 | 31.9% | 60.9% | 7.2% | 1976 |
| Mercer County (this page) | 137 | 44.5% | 36.5% | 19% | 1976 |
| Benton County | 135 | 11.9% | 67.4% | 20.7% | 1964 |
| Howard County | 133 | 42.1% | 49.6% | 8.3% | 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 Mercer 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 Mercer County, both outside Missouri so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MO (137 bridges here).
- Fremont County, CO · 137 bridges
- Prowers County, CO · 137 bridges
- Fremont County, ID · 137 bridges
- Orange County, IN · 137 bridges
Similar average build year
Nearest mean year-built outside MO (1976 here).
- Marion County, IN · avg 1976 · 958 bridges
- Mohave County, AZ · avg 1976 · 641 bridges
- Comanche County, OK · avg 1976 · 593 bridges
- Prince George's County, MD · avg 1976 · 576 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (137)
GARNER ST
FairOver: BR OF W MUDDY CRK
S 1 T 64 N R 25 W, Mercer, MO
Built 1940 Load: 0.0 t ADT: 15
BOBCAT ST
FairOver: LITTLE MEDICINE CR
S 19 T 66 N R 22 W, Mercer, MO
Built 1900 Load: 5.4 t ADT: 35
APRICOT ST
FairOver: SAND CRK
S 25 T 67 N R 24 W, Mercer, MO
Built 1950 Load: 9.0 t ADT: 15
AVALON AVE
FairOver: LITTLE MEDICINE CR
S 6 T 66 N R 22 W, Mercer, MO
Built 1936 Load: 9.9 t ADT: 35
ILLINOIS LOOP
FairOver: UP RR
S 21 T 64 N R 24 W, Mercer, MO
Built 1930 Load: 9.9 t ADT: 5
FLAGPOLE RD
FairOver: UP RR
S 6 T 65 N R 23 W, Mercer, MO
Built 1940 Load: 11.7 t ADT: 100
DOMINO PLACE
FairOver: BR OF LIT MED CRK
S 32 T 66 N R 22 W, Mercer, MO
Built 1920 Load: 12.6 t ADT: 5
JANUARY ST
FairOver: W MUDDY CR
S 6 T 63 N R 24 W, Mercer, MO
Built 1930 Load: 12.6 t ADT: 20
RT D E
FairOver: WELDON FK OF GRAND
S 28 T 64 N R 24 W, Mercer, MO
Built 1964 Load: 12.6 t ADT: 194
ARIZONA ST
FairOver: IRWIN CR
S 35 T 67 N R 23 W, Mercer, MO
Built 1900 Load: 13.5 t ADT: 30
FINCH AVE
FairOver: UP RR
S 12 T 65 N R 24 W, Mercer, MO
Built 1940 Load: 13.5 t ADT: 100
AWARD ST
FairOver: LITTLE MEDICINE CR
S 6 T 66 N R 22 W, Mercer, MO
Built 1900 Load: 14.4 t ADT: 5
RT JJ E
FairOver: E HONEY CR
S 10 T 63 N R 23 W, Mercer, MO
Built 1958 Load: 14.4 t ADT: 56
COMB AVE
FairOver: UP RR
S 31 T 66 N R 23 W, Mercer, MO
Built 1935 Load: 15.3 t ADT: 45
RT M E
FairOver: W MEDICINE CR
S 7 T 66 N R 22 W, Mercer, MO
Built 1935 Load: 16.2 t ADT: 135
AURORA ST
FairOver: IRWIN CR
S 2 T 66 N R 23 W, Mercer, MO
Built 1999 Load: 17.1 t ADT: 20
RT K E
FairOver: WELDON FK OF GRAND
S 22 T 66 N R 24 W, Mercer, MO
Built 1977 Load: 17.1 t ADT: 550
ELLIOT RD
FairOver: BR WALDON CR
S 8 T 65 N R 24 W, Mercer, MO
Built 2005 Load: 20.7 t ADT: 25
RT N E
FairOver: SANDY CR
S 10 T 65 N R 25 W, Mercer, MO
Built 1954 Load: 22.5 t ADT: 389
FLAGPOLE RD
FairOver: MUDDY CR
S 6 T 65 N R 23 W, Mercer, MO
Built 1990 Load: 23.4 t ADT: 100
US 136 E
FairOver: W MUDDY CR
S 25 T 65 N R 25 W, Mercer, MO
Built 1971 Load: 23.4 t ADT: 1,210
US 136 E
FairOver: WELDON FK OF GRAND
S 28 T 65 N R 24 W, Mercer, MO
Built 1971 Load: 23.4 t ADT: 1,883
RT M E
FairOver: WARDEN BR
S 12 T 66 N R 23 W, Mercer, MO
Built 1935 Load: 23.4 t ADT: 135
RT JJ E
FairOver: BIG N CR
S 12 T 63 N R 23 W, Mercer, MO
Built 1958 Load: 24.3 t ADT: 44
RT D E
FairOver: MARTIN CR
S 34 T 64 N R 25 W, Mercer, MO
Built 1952 Load: 25.2 t ADT: 163
RT N E
FairOver: BRUSH CR
S 7 T 65 N R 25 W, Mercer, MO
Built 1954 Load: 25.2 t ADT: 363
RT D E
FairOver: SANDY CR
S 29 T 64 N R 25 W, Mercer, MO
Built 1958 Load: 26.1 t ADT: 163
KASOTA RD
FairOver: PETEET CR
S 3 T 63 N R 25 W, Mercer, MO
Built 2005 Load: 27.9 t ADT: 5
HAGAR PL
FairOver: BR OF SANDY CREEK
S 8 T 64 N R 24 W, Mercer, MO
Built 2005 Load: 27.9 t ADT: 5
RT D E
FairOver: SOAP CR
S 31 T 64 N R 24 W, Mercer, MO
Built 1930 Load: 27.9 t ADT: 194
RT P S
FairOver: BIG BR
S 19 T 65 N R 24 W, Mercer, MO
Built 1952 Load: 28.8 t ADT: 164
RT M E
FairOver: LIT MUDDY CR
S 20 T 66 N R 23 W, Mercer, MO
Built 1934 Load: 28.8 t ADT: 574
RT D E
FairOver: WILLOW BR
S 29 T 64 N R 24 W, Mercer, MO
Built 1930 Load: 30.6 t ADT: 194
RT BB E
FairOver: BR OF WELDON FK CR
S 11 T 66 N R 24 W, Mercer, MO
Built 1961 Load: 32.4 t ADT: 166
RT P S
FairOver: BIG BR
S 18 T 65 N R 24 W, Mercer, MO
Built 2010 Load: 35.1 t ADT: 164
RT DD S
FairOver: MEDICINE CR
S 25 T 65 N R 23 W, Mercer, MO
Built 1961 Load: 36.0 t ADT: 74
ELLIOT RD
FairOver: BRUSH CR
S 20 T 66 N R 24 W, Mercer, MO
Built 2013 Load: 36.9 t ADT: 15
US 136 E
FairOver: BURRIS CR
S 6 T 65 N R 22 W, Mercer, MO
Built 1929 Load: 38.7 t ADT: 1,271
US 136 E
FairOver: WILDCAT CR
S 26 T 65 N R 24 W, Mercer, MO
Built 2006 Load: 44.1 t ADT: 889
US 136 E
FairOver: UP RR
S 26 T 65 N R 24 W, Mercer, MO
Built 2006 Load: 44.1 t ADT: 889
US 65 S
FairOver: WILDCAT CR
S 35 T 65 N R 24 W, Mercer, MO
Built 2001 Load: 45.9 t ADT: 2,170
CHER RD
FairOver: W FK LITTLE RVR
S 20 T 66 N R 24 W, Mercer, MO
Built 1994 Load: 48.6 t ADT: 40
FIREWORKS AVE
FairOver: TRIB TO MUDDY CR
S 19 T 65 N R 23 W, Mercer, MO
Built 1940 Load: 48.6 t ADT: 20
US 136 E
FairOver: W MUDDY CR
S 36 T 65 N R 25 W, Mercer, MO
Built 1971 Load: 52.2 t ADT: 1,210
US 136 E
FairOver: MARTIN CR
S 3 T 64 N R 25 W, Mercer, MO
Built 1931 Load: 57.6 t ADT: 1,074
CANNON AVE
FairOver: COAL CR
S 20 T 66 N R 25 W, Mercer, MO
Built 1999 Load: 58.5 t ADT: 15
RT E E
FairOver: COTTONWOOD BR
S 28 T 64 N R 22 W, Mercer, MO
Built 1969 Load: 58.5 t ADT: 439
US 136 E
FairOver: W MEDICINE CR
S 5 T 65 N R 22 W, Mercer, MO
Built 2002 Load: 59.4 t ADT: 1,271
IGLOO RD
FairOver: BR OF W MUDDY CR
S 30 T 64 N R 24 W, Mercer, MO
Built 1996 Load: 63.9 t ADT: 5
US 136 E
FairOver: LIT MEDICINE CR
S 2 T 65 N R 23 W, Mercer, MO
Built 2002 Load: 77.4 t ADT: 1,605
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.