Total bridges
360
Public highway bridges in Polk County
County profile · official public datasets
Polk County, FL
360 public highway bridges tracked in the FHWA National Bridge Inventory: 55.3% rated Good, 44.7% Fair, 0% Poor.
- 360
- Public bridges
- 55.3%
- Good condition
- 0%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Polk County posts a top-1% lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- Top 1%
- lowest Poor share in state
- 0%
- Poor-condition share
- 360
- public highway bridges
- 1979
- 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.
Polk County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Polk County ranks #1 of 67 Florida counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 0%). Polk County, Florida contains 360 public highway bridges. Roughly 55.3% are rated “Good,” 44.7% “Fair,” and 0% “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
55.3%
199 of 360 rated 7-9
Fair condition
44.7%
161 of 360 rated 5-6
Poor condition
0%
0 of 360 rated 4 or below
In-state Poor-share rank
#1 of 67
Among Florida counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 360 NBI-tracked bridges by lowest applicable component rating.
Good 55.3% (199)
Fair 44.7% (161)
Poor 0% (0)
47.2% of Polk County's bridges have passed the 50-year mark
170 of the 360 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 55.3% 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.
When Polk County's bridges were built
360 bridges with a recorded construction year, grouped by decade
- 1910s 1
1910–1919
1 bridges
- 1920s 7
1920–1929
7 bridges
- 1930s 10
1930–1939
10 bridges
- 1940s 23
1940–1949
23 bridges
- 1950s 27
1950–1959
27 bridges
- 1960s
1960–1969
83 bridges
- 1970s 26
1970–1979
26 bridges
- 1980s 18
1980–1989
18 bridges
- 1990s
1990–1999
89 bridges
- 2000s
2000–2009
38 bridges
- 2010s 28
2010–2019
28 bridges
- 2020s 10
2020–2029
10 bridges
What this shows Construction peaked in the 1990s, when 89 of the county's bridges still in the inventory were built, which is 24.7% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1979) matches the Florida average (1983).
How Polk County compares with Florida's closest counties by inventory size
The 5 Florida counties nearest Polk County in number of bridges, with their condition splits. Its 0% Poor share is the 1st-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1983 is in line with the group.
Showing the 5 closest of 66 Florida counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Pinellas County | 435 | 63.7% | 34.5% | 1.8% | 1983 |
| Lee County | 391 | 75.4% | 23.8% | 0.8% | 1982 |
| Collier County | 370 | 73.2% | 24.9% | 1.9% | 1981 |
| Polk County (this page) | 360 | 55.3% | 44.7% | 0% | 1979 |
| Sarasota County | 298 | 57.7% | 41.6% | 0.7% | 1982 |
| Osceola County | 255 | 62.4% | 37.6% | 0% | 1985 |
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 Polk 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 Polk County, both outside Florida so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside FL (360 bridges here).
- St. Tammany County, LA · 360 bridges
- San Mateo County, CA · 361 bridges
- Washita County, OK · 361 bridges
- Richland County, SC · 361 bridges
Similar average build year
Nearest mean year-built outside FL (1979 here).
- Pima County, AZ · avg 1979 · 1,150 bridges
- Jefferson County, KY · avg 1979 · 662 bridges
- Spartanburg County, SC · avg 1979 · 638 bridges
- McPherson County, KS · avg 1979 · 586 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (360)
SW 7TH ST.
GoodOver: LAKE SHIPP/LAKE LULU CAN
0.2MI N OF SR-655, Polk, FL
Built 1993 Load: 60.8 t ADT: 4,099
S FRONTAGE RD 5.0
GoodOver: CSXRR Beaker&WilkinsonRd
0.4MI W OF HARDEN BLVD, Polk, FL
Built 1998 Load: 61.3 t ADT: 8,600
COUNTY LINE RD.
GoodOver: HAMILTON BRANCH CANAL
0.1 MI N OF MEDULLA RD, Polk, FL
Built 1990 Load: 61.7 t ADT: 24,500
THORNHILL ROAD
GoodOver: LAKE LENA RUN
0.9MI SOUTH OF CR-540, Polk, FL
Built 2023 Load: 61.7 t ADT: 8,900
SR570 POLK EB 13.6
GoodOver: RAMP A
14.4 MI EAST OF I-4 WEST, Polk, FL
Built 1998 Load: 62.4 t ADT: 6,850
SR570 POLK RMP 0.2
GoodOver: CLARK ROAD
RMP SR 570 WB TO I-4 EB W, Polk, FL
Built 1998 Load: 64.0 t ADT: 5,900
US-17 (SR-555)
GoodOver: LK HARTRIDGE/CONINE CNL
1.4MI NOF SR-544, Polk, FL
Built 2008 Load: 66.0 t ADT: 28,000
US-17
GoodOver: WHIDDEN CREEK SO FORK
6.3 MI SOUTH OF US-98, Polk, FL
Built 1973 Load: 66.6 t ADT: 13,533
CR-64
GoodOver: ARBUCKLE CREEK
1.0MI E OF SCHOOL BUS RD, Polk, FL
Built 2003 Load: 71.2 t ADT: 1,250
US-27 (SR-25)
GoodOver: US-17 (SR-600)
US-27 & US-17 INTRSECTION, Polk, FL
Built 2000 Load: 75.3 t ADT: 56,000
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.