Total Bridges
20,753
Public highway bridges in Iowa
State profile · Above median Poor share
Iowa bridge safety
Condition ratings, load ratings, and Poor-condition data for every public highway bridge in Iowa, based on the FHWA National Bridge Inventory.
- 20,753
- Public bridges
- 36.5%
- Good condition
- 20.0%
- Poor condition
Data updated May 2026
Good Condition
36.5%
7,582 bridges rated 7-9
-13.5pp vs 50% benchmark
Poor Condition
20.0%
4,153 bridges whose lowest applicable component is rated 0-4
13.0pp vs national avg 7.0%
Iowa vs national bridge condition
Iowa - Good condition share 36.5%
National avg
Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).
Iowa - Poor-condition share 66.7%
National avg
Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.
Condition Distribution
Counties (99)
Adair 208 Adams 147 Allamakee 170 Appanoose 159 Audubon 161 Benton 327 Black Hawk 411 Boone 119 Bremer 220 Buchanan 281 Buena Vista 140 Butler 261 Calhoun 171 Carroll 223 Cass 237 Cedar 265 Cerro Gordo 210 Cherokee 223 Chickasaw 268 Clarke 150 Clay 138 Clayton 214 Clinton 325 Crawford 242 Dallas 154 Davis 156 Decatur 178 Delaware 254 Des Moines 156 Dickinson 73 Dubuque 304 Emmet 70 Fayette 288 Floyd 195 Franklin 214 Fremont 133 Greene 150 Grundy 270 Guthrie 236 Hamilton 134 Hancock 128 Hardin 211 Harrison 162 Henry 144 Howard 193 Humboldt 70 Ida 164 Iowa 189 Jackson 209 Jasper 321 Jefferson 142 Johnson 317 Jones 215 Keokuk 152 Kossuth 256 Lee 185 Linn 428 Louisa 134 Lucas 186 Lyon 241 Madison 221 Mahaska 219 Marion 204 Marshall 283 Mills 170 Mitchell 160 Monona 125 Monroe 126 Montgomery 184 Muscatine 127 O'Brien 229 Osceola 176 Page 185 Palo Alto 114 Plymouth 407 Pocahontas 186 Polk 415 Pottawattamie 469 Poweshiek 221 Ringgold 206 Sac 188 Scott 212 Shelby 194 Sioux 429 Story 262 Tama 307 Taylor 220 Union 153 Van Buren 142 Wapello 160 Warren 231 Washington 203 Wayne 163 Webster 179 Winnebago 48 Winneshiek 317 Woodbury 379 Worth 89 Wright 168
Iowa vs nearby ranks
Adjacent states by Poor-condition share (lower share = better)
States are ranked by the share of bridges whose lowest applicable component rating is 4 or below. This describes recorded condition; it does not measure funding effectiveness or live crossing safety. States here sit immediately above and below Iowa on the same metric.
WV
West Virginia
16.02% top marginal rate
SD
South Dakota
16.24% top marginal rate
IA
Iowa
20.01% top marginal rate
VI
Virgin Islands
29.17% top marginal rate
Bridges Needing Most Attention in Iowa
Six lowest-condition bridges in Iowa, ranked by the portal's composite display score. Inspection intervals are risk-based under current NBIS rules.
270TH STREET
PoorOver: ROSE BRANCH
071343401, Adams, IA
Built 1976 Load: 2.7 t ADT: 79
LOCAL
PoorOver: CREEK
078342601, Audubon, IA
Built 1935 Load: 2.7 t ADT: 21
KLINE RD
PoorOver: MUD CREEK
87-12-15-02-10, Black Hawk, IA
Built 1948 Load: 2.7 t ADT: 11
LOCAL - 700TH
PoorOver: TRIB TROUBLESOME CREEK
077351402, Cass, IA
Built 1983 Load: 2.7 t ADT: 11
LOCAL - DAYTONA
PoorOver: BUCK CREEK
077361903, Cass, IA
Built 1980 Load: 2.7 t ADT: 35
100TH ST.
PoorOver: UNION CREEK
083E20101, Clinton, IA
Built 1900 Load: 2.7 t ADT: 78
All Bridges in Iowa
T-53 (S AVE)
UnknownOver: US 20
2.0 mi. W of SR T55, Grundy, IA
Built 1999 ADT: 13,600
US 20 EB
UnknownOver: SR T55
AT JUNCTION WITH SR T55, Grundy, IA
Built 2000 ADT: 945
WB US 20
UnknownOver: SR T55
AT JUNCTION WITH SR T55, Grundy, IA
Built 2000 ADT: 945
US 20 EB
UnknownOver: IA 14
AT JUNCTION IA 14, Grundy, IA
Built 2000 ADT: 2,400
T47 (Q AVE)
UnknownOver: US 20
3.0 MILES E OF JCT IA 14, Grundy, IA
Built 1999 ADT: 13,600
VISTA AVE
UnknownOver: US 20
1.6 MILES EAST OF SR T55, Grundy, IA
Built 1999 ADT: 14,500
US 20 WB
UnknownOver: IA 14
AT JUNCTION WITH IA 14, Grundy, IA
Built 2000 ADT: 2,400
D AVENUE
UnknownOver: US 20
2.0 MILES W OF JCT SR T19, Grundy, IA
Built 2003 ADT: 9,900
B AVENUE
UnknownOver: US 20
4.0 MILES W OF JCT SR T19, Grundy, IA
Built 2003 ADT: 9,900
L AVENUE
UnknownOver: US 20
2.0 MILES W OF JCT IA 14, Grundy, IA
Built 2003 ADT: 10,100
J AVENUE
UnknownOver: US 20
4.0 MILES W OF JCT IA 14, Grundy, IA
Built 2003 ADT: 10,100
US 20 WB
UnknownOver: H AVENUE
2.0 MILES EAST JCT SR T19, Grundy, IA
Built 2003 ADT: 50
US 20 EB
UnknownOver: H AVENUE
2.0 mi. E of jct SR T19, Grundy, IA
Built 2003 ADT: 50
US 20 WB
UnknownOver: SR T19
AT JUNCTION WITH SR T19, Grundy, IA
Built 2003 ADT: 740
US 20 EB
UnknownOver: T 19
AT JUNCTION WITH SR T19, Grundy, IA
Built 2003 ADT: 740
SR D-65
UnknownOver: I-35
AT JUNCTION WITH I-35, Hamilton, IA
Built 1965 ADT: 26,100
NB I-35
UnknownOver: CO RD D-25
AT JUNCTION WITH SR D25, Hamilton, IA
Built 1974 ADT: 1,090
I 35 SB
UnknownOver: SR D25
AT JUNCTION WITH SR D25, Hamilton, IA
Built 1974 ADT: 1,090
NB I-35
UnknownOver: CC RR & 210TH ST
1.1 MI N OF SR D25, Hamilton, IA
Built 1972 ADT: 40
SR D-20
UnknownOver: I-35
AT JUNCTION WITH D20, Hamilton, IA
Built 1972 ADT: 16,000
SB I-35
UnknownOver: CC RR & 210TH ST
1.1 MILES NORTH OF SR D25, Hamilton, IA
Built 1972 ADT: 20
LOCKWOOD AVE
UnknownOver: US 20
3.0 MILE E OF E JCT IA 17, Hamilton, IA
Built 1975 ADT: 10,100
EB US 20
UnknownOver: R-38
AT JUNCTION WITH SR R38, Hamilton, IA
Built 1975 ADT: 235
WB US 20
UnknownOver: R-38
AT JUNCTION WITH SR R38, Hamilton, IA
Built 1975 ADT: 235
POPLAR GROVE AVE
UnknownOver: US 20
2.0 MILES W OF JCT US 69, Hamilton, IA
Built 1975 ADT: 10,300
IA 17
UnknownOver: US 20
AT NORTH JCT WITH US 20, Hamilton, IA
Built 1978 ADT: 9,700
EB 20 & SB 17
UnknownOver: R-27
0.8 MI W OF E JCT IA 17, Hamilton, IA
Built 1978 ADT: 475
WB 20 & NB 17
UnknownOver: R-27
0.8 MI W OF E JCT IA 17, Hamilton, IA
Built 1978 ADT: 475
CO RD R 61
UnknownOver: U.S. 20
0.5 MILE EAST OF JCT I-35, Hamilton, IA
Built 1990 ADT: 3,450
FM RD R 77
UnknownOver: US 20
2.5 MILES E OF JCT I-35, Hamilton, IA
Built 1990 ADT: 8,700
ZIEGLER AVE
UnknownOver: US 20
2.0 MILES EAST OF SR R77, Hamilton, IA
Built 1990 ADT: 8,900
EB US 20
UnknownOver: CO RD S-27
AT JUNCTION WITH SR S27, Hardin, IA
Built 1990 ADT: 545
WB US 20
UnknownOver: CO RD S-27
AT JUNCTION WITH SR S27, Hardin, IA
Built 1990 ADT: 545
D AVENUE
UnknownOver: US 20
2.0 MILES W OF SR S27, Hardin, IA
Built 1990 ADT: 9,600
H AVENUE
UnknownOver: US 20
2.0 MILES E OF JCT SR S27, Hardin, IA
Built 1990 ADT: 9,400
JJ AVENUE
UnknownOver: US 20
2.0 MILES W OF JCT US 65, Hardin, IA
Built 1990 ADT: 9,400
US 20 EB
UnknownOver: US 65
AT JUNCTION WITH US 65, Hardin, IA
Built 2003 ADT: 1,820
US 20 WB
UnknownOver: US 65
AT JUNCTION WITH US 65, Hardin, IA
Built 2003 ADT: 1,820
US 20 EB
UnknownOver: D 35 (ELM ST)
3.4 MILES E OF JCT US 65, Hardin, IA
Built 2003 ADT: 125
US 20 WB
UnknownOver: D 35 (ELM ST)
3.4 MILES E OF JCT US 65, Hardin, IA
Built 2003 ADT: 125
V AVENUE
UnknownOver: US 20
2.4 MILES W OF JCT SR S56, Hardin, IA
Built 2003 ADT: 9,300
T AVENUE
UnknownOver: US 20
1.2 MILES E OF JCT SR D35, Hardin, IA
Built 2003 ADT: 9,300
D35
UnknownOver: US 20
AT JUNCTION SR D35, Hardin, IA
Built 2003 ADT: 9,000
S 56
UnknownOver: US 20
AT JUNCTION WITH SR S56, Hardin, IA
Built 2003 ADT: 9,500
LOCAL RD
UnknownOver: I-29
1.0 MI. N OF JCT. US 30, Harrison, IA
Built 1966 ADT: 16,100
SR X-23
UnknownOver: RELOC. US 34
At Jct. U.S. 34, Henry, IA
Built 1998 ADT: 5,500
255TH STREET
UnknownOver: U.S. 218
1.8 mi. S of S Jct. US 34, Henry, IA
Built 2001 ADT: 7,000
S IRIS ST
UnknownOver: US 218
0.4 mi. S of S Jct. US 34, Henry, IA
Built 2001 ADT: 5,800
US 218 NB
UnknownOver: US 34
At the S Jct. U.S. 34, Henry, IA
Built 2001 ADT: 840
US 218 SB
UnknownOver: US 34
At S jct. US 34, Henry, IA
Built 2001 ADT: 840
Showing 301-350 of 20,753 bridges
Related
Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges.
Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the FHWA National Bridge Inventory (NBI). Poor condition is an inspection-record category, not a closure or unsafe-to-cross designation. Consult the bridge owner for current status.
Understanding Bridge Conditions
How FHWA rates bridge condition on a 0-9 scale.
Check Your Daily Bridges
How to look up bridge condition data for bridges on your route.
Read our methodology — how this data is sourced, computed, and verified.
Every figure on PlainBridge 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.