Total bridges
199
Public highway bridges in Dallas County
County profile · official public datasets
Dallas County, IA
199 public highway bridges tracked in the FHWA National Bridge Inventory: 44.7% rated Good, 46.2% Fair, 9% Poor.
- 199
- Public bridges
- 44.7%
- Good condition
- 9%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Dallas County posts a top-quartile lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- Top 15%
- lowest Poor share in state
- 9%
- Poor-condition share
- 199
- public highway bridges
- 1978
- 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.
Dallas County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Dallas County ranks #15 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9%). Dallas County, Iowa contains 199 public highway bridges. Roughly 44.7% are rated “Good,” 46.2% “Fair,” and 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
44.7%
89 of 199 rated 7-9
Fair condition
46.2%
92 of 199 rated 5-6
Poor condition
9%
18 of 199 rated 4 or below
In-state Poor-share rank
#15 of 99
Among Iowa counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 199 NBI-tracked bridges by lowest applicable component rating.
Good 44.7% (89)
Fair 46.2% (92)
Poor 9% (18)
Dallas County's Poor-condition bridges carry 11,710 vehicle crossings a day
That is 2.1% of the county's reported daily bridge traffic on 9.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 651 crossings a day against 1,779 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 198 of 199 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
42.2% of Dallas County's bridges have passed the 50-year mark
84 of the 199 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 44.7% 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 22.4% of the county's Poor-condition bridge traffic
FM over JOHNSON CREEK, built 1933, carries 2,628 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 18-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 11,710 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Dallas County's bridges were built
199 bridges with a recorded construction year, grouped by decade
- pre-1900 2
Built before 1900
2 bridges
- 1900s 3
1900–1909
3 bridges
- 1910s 5
1910–1919
5 bridges
- 1920s 9
1920–1929
9 bridges
- 1930s 9
1930–1939
9 bridges
- 1940s 5
1940–1949
5 bridges
- 1950s 10
1950–1959
10 bridges
- 1960s
1960–1969
31 bridges
- 1970s
1970–1979
29 bridges
- 1980s
1980–1989
22 bridges
- 1990s
1990–1999
13 bridges
- 2000s
2000–2009
28 bridges
- 2010s
2010–2019
26 bridges
- 2020s 7
2020–2029
7 bridges
What this shows Construction peaked in the 1960s, when 31 of the county's bridges still in the inventory were built, which is 15.6% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1978) matches the Iowa average (1979).
How Dallas County compares with Iowa's closest counties by inventory size
The 5 Iowa counties nearest Dallas County in number of bridges, with their condition splits. Its 9% Poor share is the 1st-lowest of these 6. Its average build year of 1978 against a peer-group mean of 1973 is 5 years newer.
Showing the 5 closest of 98 Iowa counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Pocahontas County | 201 | 19.4% | 55.2% | 25.4% | 1974 |
| Dallas County (this page) | 199 | 44.7% | 46.2% | 9% | 1978 |
| Allamakee County | 197 | 31.5% | 59.4% | 9.1% | 1975 |
| Calhoun County | 197 | 24.4% | 50.3% | 25.4% | 1971 |
| Decatur County | 197 | 18.3% | 41.1% | 40.6% | 1972 |
| Page County | 196 | 24% | 43.9% | 32.1% | 1975 |
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 Dallas 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 Dallas County, both outside Iowa so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside IA (199 bridges here).
- Montgomery County, AR · 199 bridges
- Warren County, IL · 199 bridges
- Leake County, MS · 199 bridges
- Neshoba County, MS · 199 bridges
Similar average build year
Nearest mean year-built outside IA (1978 here).
- Orange County, CA · avg 1978 · 1,164 bridges
- Sumner County, KS · avg 1978 · 659 bridges
- Allen County, IN · avg 1978 · 613 bridges
- Livingston County, IL · avg 1978 · 579 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (92)
COUNTY ROAD
FairOver: PANTHER CREEK
080283102, Dallas, IA
Built 1935 Load: 31.2 t ADT: 21
FM
FairOver: PANTHER CREEK
080292301, Dallas, IA
Built 1967 Load: 31.4 t ADT: 170
EB I-80
FairOver: NORTH RACCOON RIVER
2.3 MI. E. OF JCT. US 169, Dallas, IA
Built 1966 Load: 31.7 t ADT: 18,750
WB I-80
FairOver: NORTH RACCOON RIVER
2.3 MI. E OF JCT. 169, Dallas, IA
Built 1966 Load: 31.7 t ADT: 18,750
R 30 (W AVE)
FairOver: WALNUT CREEK
079261104, Dallas, IA
Built 1975 Load: 32.7 t ADT: 3,018
W AVE
FairOver: LITTLE WALNUT CREEK
079262300, Dallas, IA
Built 1975 Load: 32.7 t ADT: 3,612
FM
FairOver: TRIB. TO SUGAR CREEK
078260502, Dallas, IA
Built 2000 Load: 32.7 t ADT: 3,636
UTICA TRAIL
FairOver: TRIB OF RACCOON RIVER
078263105, Dallas, IA
Built 1994 Load: 32.7 t ADT: 289
68TH STREET
FairOver: CREEK
O54200475, Dallas, IA
Built 2003 Load: 32.7 t ADT: 1,216
BROOKVIEW LN
FairOver: DD
078272700, Dallas, IA
Built 2004 Load: 32.7 t ADT: 58
US 169
FairOver: BULGER CREEK & IAIS RR
1.1 mi. S of Jct. I-80, Dallas, IA
Built 1997 Load: 32.8 t ADT: 6,600
IA 141
FairOver: NORTH RACCOON RIVER
1.5 mi. W of IA 144, Dallas, IA
Built 1976 Load: 33.3 t ADT: 3,570
LOCAL
FairOver: SMALL STREAM
078283603, Dallas, IA
Built 1954 Load: 33.7 t ADT: 807
WB I-80
FairOver: CO RD (P-57)
At the Jct. SR P57, Dallas, IA
Built 1966 Load: 33.8 t ADT: 14,550
FM
FairOver: SO RACCOON RIVER
078281610, Dallas, IA
Built 1993 Load: 34.7 t ADT: 1,474
JORDAN CR PKWY
FairOver: CREEK
000000000, Dallas, IA
Built 2003 Load: 34.8 t ADT: 14,127
EB IA 141
FairOver: FROG CREEK
0.1 MILE W OF JCT IA 144, Dallas, IA
Built 1976 Load: 34.9 t ADT: 2,210
FM
FairOver: NORTH RACCOON RIVER
081280801, Dallas, IA
Built 1980 Load: 36.2 t ADT: 139
WB IA 141
FairOver: BEAVER CREEK
1.3 mi. E OF JCT. US 169, Dallas, IA
Built 1978 Load: 36.6 t ADT: 4,300
FM
FairOver: RACCOON RIVER OVERFLOW
078263005, Dallas, IA
Built 1973 Load: 36.9 t ADT: 1,942
COUNTY ROAD
FairOver: PANTHER CREEK
079280801, Dallas, IA
Built 1988 Load: 37.1 t ADT: 21
EB I-80
FairOver: CO RD (P-57)
AT SR P57 JUNCTION, Dallas, IA
Built 1966 Load: 37.4 t ADT: 14,550
I 80 WB
FairOver: US 169
AT JCT. OF U.S. 169, Dallas, IA
Built 1966 Load: 37.4 t ADT: 14,950
I 80 EB
FairOver: US 6/169
At the Jct. US 6 & US 169, Dallas, IA
Built 1966 Load: 37.7 t ADT: 14,950
EB I-80
FairOver: SUGAR CREEK
7.9 MI. E OF JCT. US 169, Dallas, IA
Built 1966 Load: 38.0 t ADT: 24,050
WB IA 141
FairOver: LITTLE BEAVER CREEK
2.2 MI WEST OF JCT IA 210, Dallas, IA
Built 1983 Load: 38.2 t ADT: 4,300
IA 210
FairOver: IA 141
AT JCT. OF IA #141, Dallas, IA
Built 1997 Load: 38.3 t ADT: 1,850
EB I-80
FairOver: OVER UP RR
2.3 MI. W OF W JCT. I-35, Dallas, IA
Built 1966 Load: 38.4 t ADT: 26,850
US 169
FairOver: NORTH RACCOON RIVER
1.4 mi. N of jct. US 6, Dallas, IA
Built 1972 Load: 38.6 t ADT: 4,760
WB I-80
FairOver: OVER UP RR
2.3 MI. W OF W JCT I-35, Dallas, IA
Built 1966 Load: 39.5 t ADT: 26,850
F60 OLD HWY 6
FairOver: SOUTH RACCOON RIVER
078290904, Dallas, IA
Built 1978 Load: 41.8 t ADT: 1,446
EB IA 141
FairOver: US 169
AT JUNCTION OF US 169, Dallas, IA
Built 1978 Load: 48.9 t ADT: 3,700
US 169
FairOver: N RACCOON RIVER OVERFLOW
0.6 mi. N of Jct. US 6, Dallas, IA
Built 1994 Load: 49.1 t ADT: 4,720
US 6
FairOver: NORTH RACCOON RIVER
0.3 mi. E of E Jct US 169, Dallas, IA
Built 1977 Load: 49.3 t ADT: 9,200
WB IA 141
FairOver: US 169
AT JUNCTION OF US 169, Dallas, IA
Built 1978 Load: 50.4 t ADT: 3,700
FM
FairOver: SOUTH RACCOON RIVER
078272106, Dallas, IA
Built 1979 Load: 51.5 t ADT: 170
WB IA 141
FairOver: FROG CREEK
0.1 MILES W OF JCT IA 144, Dallas, IA
Built 1976 Load: 52.0 t ADT: 2,210
LOCAL
FairOver: BEAR CREEK
078283002, Dallas, IA
Built 1999 Load: 52.9 t ADT: 247
US 169
FairOver: BEAVER CREEK
0.9 MI. N OF JCT. IA 141, Dallas, IA
Built 1988 Load: 53.2 t ADT: 3,990
FM
FairOver: SMALL STREAM
078273301, Dallas, IA
Built 1953 Load: 99.9 t ADT: 1,664
FM
FairOver: STREAM
078260803, Dallas, IA
Built 1963 Load: 99.9 t ADT: 2,281
COUNTY ROAD
FairOver: CREEK
081282004, Dallas, IA
Built 1909 Load: 99.9 t ADT: 103
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.