Hamilton County, IA

134 public highway bridges

Hamilton County Bridge Snapshot

Hamilton County, Iowa contains 134 public highway bridges in the FHWA National Bridge Inventory. Roughly 32.1% are rated “Good,” 31.3% “Fair,” 24.6% “Poor,” and 24.6% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in IA are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

134

Total Bridges

32.1%

Good

24.6%

Poor

24.6%

Structurally Deficient

Condition Distribution

Good

32.1% (43)

Fair

31.3% (42)

Poor

24.6% (33)

SD

24.6% (33)

All Bridges (134)

Sort:

US 20

Over: DRAINAGE DITCH #4

1.8 MILES EAST OF US 69, Hamilton, IA

Built 1968 Load: 40.2 t ADT: 9,600

I 35 NB

Over: STREAM

1.8 MILES N OF SEC RD D20, Hamilton, IA

Built 1972 Load: 42.0 t ADT: 8,200

SB I-35

Over: STREAM

1.8 MILES N OF SEC RD D20, Hamilton, IA

Built 1972 Load: 42.0 t ADT: 8,200

OVERPASS DR

Over: CC RR

000000000, Hamilton, IA

Built 1931 Load: 47.7 t ADT: 3,353

FM

Over: IOWAY CREEK

086262202, Hamilton, IA

Built 1982 Load: 56.9 t ADT: 559

LOCAL

Over: DRAINAGE DITCH

087240703, Hamilton, IA

Built 1971 Load: 99.9 t ADT: 20

FM

Over: DRAINAGE DITCH

087253601, Hamilton, IA

Built 1976 Load: 99.9 t ADT: 509

FM

Over: BUCK CREEK

089252206, Hamilton, IA

Built 1975 Load: 99.9 t ADT: 199

I 35

Over: STREAM

0.3 MILE NORTH OF SR D65, Hamilton, IA

Built 1965 Load: 28.8 t ADT: 26,800

370TH ST

Over: DRAINAGE DITCH

086262401, Hamilton, IA

Built 2017 Load: 32.4 t ADT: 20

D41 280TH ST

Over: CREEK

087250203, Hamilton, IA

Built 2015 Load: 32.4 t ADT: 234

280TH ST

Over: BOONE RIVER

087250601, Hamilton, IA

Built 2019 Load: 32.4 t ADT: 80

ZIEGLER AVE

Over: BEAR CR

086232402, Hamilton, IA

Built 2012 Load: 32.7 t ADT: 60

380TH ST

Over: LONG DICK CREEK

086232701, Hamilton, IA

Built 2000 Load: 32.7 t ADT: 797

FM

Over: LONG DICK CREEK

086233504, Hamilton, IA

Built 1997 Load: 32.7 t ADT: 559

LOCAL

Over: KEIGLEY CREEK

086252201, Hamilton, IA

Built 1994 Load: 32.7 t ADT: 50

FM

Over: KEIGLEY CREEK

086252501, Hamilton, IA

Built 1999 Load: 32.7 t ADT: 589

LOCAL

Over: PRAIRIE CR

087262003, Hamilton, IA

Built 2006 Load: 32.7 t ADT: 26

FM

Over: DRAINAGE DITCH

088233601, Hamilton, IA

Built 2005 Load: 32.7 t ADT: 265

LOCAL

Over: DRAINAGE DITCH

088241402, Hamilton, IA

Built 2011 Load: 32.7 t ADT: 11

240TH ST

Over: DRAINAGE DITCH

088241501, Hamilton, IA

Built 2011 Load: 32.7 t ADT: 50

TOLLMAN AVE

Over: DRAINAGE DITCH

088242402, Hamilton, IA

Built 2012 Load: 32.7 t ADT: 45

FM

Over: BREWERS CREEK

088261003, Hamilton, IA

Built 1978 Load: 32.7 t ADT: 131

160TH ST

Over: DRAINAGE DITCH

089230201, Hamilton, IA

Built 2010 Load: 32.7 t ADT: 30

170TH ST

Over: DRAINAGE DITCH

089230801, Hamilton, IA

Built 2012 Load: 32.7 t ADT: 11

LOCAL

Over: DRAINAGE DITCH

089231003, Hamilton, IA

Built 2005 Load: 32.7 t ADT: 11

LOCAL

Over: BUCK CR

089250103, Hamilton, IA

Built 2008 Load: 32.7 t ADT: 26

175TH ST

Over: BUCK CREEK

089251203, Hamilton, IA

Built 2000 Load: 32.7 t ADT: 30

MCMURRAY AVE

Over: KEIGLEY BRANCH

086252302, Hamilton, IA

Built 2017 Load: 33.0 t ADT: 34

IA 175

Over: UP RR

0.5 MILE E OF E JCT US 69, Hamilton, IA

Built 1979 Load: 34.5 t ADT: 1,690

203RD ST

Over: LYON CREEK

089252603, Hamilton, IA

Built 2019 Load: 34.7 t ADT: 40

FM

Over: BOONE RIVER

089260104, Hamilton, IA

Built 2009 Load: 34.9 t ADT: 509

LOCAL

Over: PRAIRIE CR

087260503, Hamilton, IA

Built 2008 Load: 35.6 t ADT: 20

LOCAL

Over: SKUNK RIVER

087242402, Hamilton, IA

Built 1993 Load: 36.4 t ADT: 30

LOCAL

Over: IOWAY CREEK

086262602, Hamilton, IA

Built 1988 Load: 37.4 t ADT: 11

280TH ST

Over: SKUNK RIVER

087240101, Hamilton, IA

Built 2020 Load: 38.2 t ADT: 34

360TH ST

Over: SKUNK RIVER

086241405, Hamilton, IA

Built 2013 Load: 39.9 t ADT: 80

260TH ST

Over: DRAINAGE DITCH

088232501, Hamilton, IA

Built 2017 Load: 40.5 t ADT: 34

I-35

Over: DRAINAGE DITCH 23 & 31

1.0 MILE N OF JCT SR D20, Hamilton, IA

Built 1972 Load: 41.1 t ADT: 16,400

LOCAL

Over: DRAINAGE DITCH

087242801, Hamilton, IA

Built 2006 Load: 41.5 t ADT: 379

FM

Over: LONG DICK CREEK

086233504, Hamilton, IA

Built 1997 Load: 43.2 t ADT: 559

BEACH ST

Over: BREWERS CREEK

088261204, Hamilton, IA

Built 1995 Load: 45.5 t ADT: 1,745

390TH ST

Over: DRAINAGE DITCH

086263203, Hamilton, IA

Built 2004 Load: 47.0 t ADT: 20

XIRCUS AVE

Over: LONG DICK CREEK

086232202, Hamilton, IA

Built 2022 Load: 47.3 t ADT: 30

LOCAL

Over: CREEK

086241102, Hamilton, IA

Built 2006 Load: 48.2 t ADT: 71

LOCAL

Over: WHITE FOX CREEK

089252803, Hamilton, IA

Built 1994 Load: 52.9 t ADT: 34

LOCAL

Over: IOWAY CREEK

086262101, Hamilton, IA

Built 1991 Load: 56.9 t ADT: 71

LOCAL

Over: BUCK CREEK

089251405, Hamilton, IA

Built 1994 Load: 58.4 t ADT: 71

US 20

Over: DRAINAGE DITCH #4

0.7 MILE E OF JCT US 69, Hamilton, IA

Built 1968 Load: 61.6 t ADT: 9,600

FM

Over: DRAINAGE DITCH

087251108, Hamilton, IA

Built 2004 Load: 99.9 t ADT: 249

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial

Reviewed byPlainbridges Editorial, Plain Bridges Editorial Team · June 5, 2026