National Bridge Inventory: Iowa



  • The state has identified needed repairs on 14,853 bridges.
  • This compares to 15,135 bridges that needed work in 2021.
  • Over the life of the IIJA, Iowa will receive a total of $467.1 million in bridge formula funds, which will help make needed repairs.
  • Iowa currently has access to $373.6 million of that total, and has committed $150.2 million towards 197 projects as of June 2025.
  • Of the 23,716 bridges in the state, 4,423, or 18.6 percent, are classified as structurally deficient. This means one of the key elements is in poor or worse condition.
  • This is down from 4,504 bridges classified as structurally deficient in 2021.
  • The deck area of structurally deficient bridges accounts for 1.3 percent of total deck area on all structures.

Top Most Traveled Structurally Deficient Bridges in Iowa

County Year Built Daily Crossings Type of Bridge Location
Scott 1940 26,500 Urban other principal arterial Centennial Bridge
Woodbury 1936 20,600 Urban other principal arterial Ia 12 over BNSF,Rvr, Sts, & Ia 376
Jasper 1960 18,050 Rural Interstate WB I-80 over Sugar Creek
Polk 1936 15,634 Urban other principal arterial Fleur Dr over Old UP RR & SW 22nd
Scott 1900 15,300 Urban minor arterial Eastern Ave over Duck Creek
Polk 1967 14,108 Urban minor arterial Sw 9th St over Cherry, RR, Mlk Pkwy
Johnson 1972 14,025 Urban minor arterial Gilbert St over Ralston Creek
Plymouth 1926 14,000 Rural arterial US 75 over Stream
Poweshiek 1963 13,300 Rural Interstate I 80 WB over Iowa 21
Polk 1967 12,809 Urban minor arterial Sw 9th St over Raccoon River & Trail
Lee 1915 10,953 Urban minor arterial Ave L over Dry Creek
Johnson 1915 10,950 Urban other principal arterial Ia 1 NB over Iowa River
Linn 1988 10,789 Urban minor arterial 8th Ave over Indian Creek
Marshall 1951 10,448 Urban minor arterial So Center St over Linn Creek
Linn 1969 10,268 Urban other principal arterial Edgewood Rd NE over Cedar River & RR
Scott 1978 10,200 Urban minor arterial Eastern Ave over Goose Creek
Linn 1968 9,703 Urban minor arterial Center Point Rd over Cc RR
Marshall 1951 9,491 Urban minor arterial So Center St over RR and Madison St
Linn 1938 9,382 Urban other principal arterial 8th Ave over Cedar River
Woodbury 1962 8,957 Urban minor arterial 6th St over Floyd River
Webster 1955 8,894 Urban other principal arterial 5th Ave over drainage Ditch
Webster 1974 8,798 Urban minor arterial N 15th St over Soldier Creek
Black Hawk 1950 8,392 Urban minor arterial E Ridgeway Ave over Dry Run Creek
Story 1957 8,224 Urban other principal arterial Lincoln Way over Ioway Creek
Polk 1976 7,911 Urban minor arterial Se 6th St over Des Moines River

Bridge Inventory: Iowa

Type of Bridge Number of Bridges Area of All Bridges
(sq. meters)
Daily Crossings on All Bridges Number of Structurally Deficient Bridges Area of Structurally Deficient Bridges
(sq. meters)
Daily Crossings on Structurally Deficient Bridges
Rural Interstate 379 392,000 5,029,225 2 1,079 31,350
Rural arterial 1,280 58,710,010 5,712,190 4 2,380 24,890
Rural minor arterial 1,072 619,280 2,036,216 20 12,577 37,297
Rural major collector 3,427 1,286,361 2,559,638 653 237,604 415,708
Rural minor collector 3,859 1,015,181 550,027 718 148,921 83,391
Rural local road 11,294 1,855,528 612,570 2,857 324,933 122,124
Urban Interstate 346 781,917 8,080,230 0 0 0
Urban freeway/expressway 0 0 0 0 0 0
Urban other principal arterial 653 1,157,295 5,708,768 9 62,912 117,940
Urban minor arterial 559 628,911 3,283,635 52 74,971 296,864
Urban collector 323 205,170 823,003 29 17,304 50,299
Urban local road 524 205,356 416,671 79 18,861 53,155
Total 23,716 66,857,008 34,812,173 4,423 901,542 1,233,018

Proposed Bridge Work

Type of Work Number of Bridges Cost to Repair
(in millions)
Daily Crossings Area of Bridges
(sq. meters)
Bridge replacement 6,043 $1,585 1,278,204 1,059,001
Widening & rehabilitation 52 $27 103,875 26,217
Rehabilitation 1,083 $412 897,776 400,859
Deck rehabilitation/replacement 37 $19 37,415 18,679
Other structural work 7,638 $2,068 3,044,169 59,700,678
Total 14,853 $4,111 5,361,439 61,205,434

About the data:

Data and cost estimates are from the Federal Highway Administration (FHWA) National Bridge Inventory (NBI), downloaded on June 24, 2025. Note that specific conditions on bridges may have changed as a result of recent work or updated inspections.

Effective January 1, 2018, FHWA changed the definition of structurally deficient as part of the final rule on highway and bridge performance measures, published May 20, 2017 pursuant to the 2012 federal aid highway bill Moving Ahead for Progress in the 21st Century Act (MAP-21). Two measures that were previously used to classify bridges as structurally deficient are no longer used. This includes bridges where the overall structural evaluation was rated in poor or worse condition, or where the adequacy of waterway openings was insufficient.

The new definition limits the classification to bridges where one of the key structural elements—the deck, superstructure, substructure or culverts, are rated in poor or worse condition. During inspection, the conditions of a variety of bridge elements are rated on a scale of 0 (failed condition) to 9 (excellent condition). A rating of 4 is considered “poor” condition.

Cost estimates have been derived by ARTBA, based on 2023 average bridge replacement costs for structures on and off the National Highway System, published by FHWA. Bridge rehabilitation costs are estimated to be 68 percent of replacement costs. A bridge is considered to need repair if the structure has identified repairs as part of the NBI, a repair cost estimate is supplied by the bridge owner or the bridge is classified as structurally deficient. Please note that for a few states, the number of bridges needing to be repaired can vary significantly from year to year, and reflects the data entered by the state.

Bridges are classified by FHWA into types based on the functional classification of the roadway on the bridge. Interstates comprise routes officially designated by the Secretary of Transportation. Other principal arterials serve major centers of urban areas or provide mobility through rural areas. Freeways and expressways have directional lanes generally separated by a physical barrier, and access/egress points generally limited to on- and off-ramps. Minor arterials serve smaller areas and are used for trips of moderate length. Collectors funnel traffic from local roads to the arterial network; major collectors have higher speed limits and traffic volumes and are longer in length and spaced at greater intervals, while minor collectors are shorter and provide service to smaller communities. Local roads do not carry through traffic and are intended for short distance travel.

1
Compared to 1 in 2024

in the nation in % of structurally deficient bridges

1. Iowa 19.0%
2. West Virginia 18.0%

1
Compared to 1 in 2024

in the nation in # of structurally deficient bridges

1. Iowa 4,424
2. Pennsylvania 2,813

47
Compared to 8 in 2024

in the nation in % of structurally deficient bridge deck area

1. West Virginia 13.0%
47. Iowa 1.0%
48. Florida 1.0%
Full State Ranking

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  • Source: Data is from the Federal Highway Administration (FHWA) National Bridge Inventory (NBI), downloaded on June 24, 2025. Note that specific conditions on bridges may have changed as a result of recent work or updated inspections.

    ARTBA is a non-partisan federation whose primary goal is to aggressively grow and protect transportation infrastructure investment to meet the public and business demand for safe and efficient travel.

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