National Bridge Inventory: South Dakota


  • The state has identified needed repairs on 2,192 bridges.
  • This compares to 2,404 bridges that needed work in 2021.
  • Over the life of the IIJA, South Dakota will receive a total of $225.0 million in bridge formula funds, which will help make needed repairs.
  • South Dakota currently has access to $180.0 million of that total, and has committed $65.9 million towards 62 projects as of June 2025.
  • Of the 5,883 bridges in the state, 945, or 16.1 percent, are classified as structurally deficient. This means one of the key elements is in poor or worse condition.
  • This is down from 1,018 bridges classified as structurally deficient in 2021.
  • The deck area of structurally deficient bridges accounts for 8.4 percent of total deck area on all structures.

Top Most Traveled Structurally Deficient Bridges in South Dakota

CountyYear BuiltDaily CrossingsType of BridgeLocation
Brown195421,635Urban other principal arterialUS012 over Moccasin Ck
Minnehaha197913,800Rural minor arterial49th Street over Big Sioux River
Minnehaha19869,363Urban minor arterialS. Cliff Avenue over Big Sioux River
Minnehaha19898,815Rural InterstateI090 W over Sd038
Union19608,020Rural InterstateI029 N over 302 St (Fas 6372)
Moody19667,985Rural InterstateI029 N over Big Sioux Rv
Moody19667,985Rural InterstateI029 S over Big Sioux Rv
Hughes19507,155Urban minor arterialCapitol Ave over Capitol Lake Outlet
Minnehaha19755,300Urban minor arterialRiver Boulevard over Big Sioux River
Codington19744,970Urban minor arterial14th Ave. N, Wtn. over Big Sioux Rv
Pennington19744,700Urban collectorChapel Lane over Rapid Ck
Brule19524,431Rural minor arterialSd050 over R&W RR
Lawrence19883,981Urban collectorGrant Street over Spearfish Ck
Yankton19763,980Urban collectorW 23rd Street over Marne Creek
Davison19463,776Rural arterialSd037 over Ck
Beadle19603,601Urban other principal arterialUS014 over James Rv
Minnehaha19533,442Rural minor arterialSd011 over West Pipestone Ck
Brown19593,041Rural arterialUS281 over Elm Rv
Edmunds19742,666Rural arterialUS012 over Ck
Lyman19532,622Rural local roadI090 Wf over R&W RR
Grant19142,560Urban local road2nd Avenue over BNSF Railroad
Minnehaha19662,419Rural major collector258th St, Hwy 130 over Big Sioux River
Pennington19472,378Rural arterialUS385 over Horse Ck
Brown19742,069Urban collector10th Avenue SE over Moccasin Creek
Lawrence19342,000Rural major collectorCounty Rd 014B over Miller Ck

Bridge Inventory: South Dakota

Type of BridgeNumber of BridgesArea of All Bridges
(sq. meters)
Daily Crossings on All BridgesNumber of Structurally Deficient BridgesArea of Structurally Deficient Bridges
(sq. meters)
Daily Crossings on Structurally Deficient Bridges
Rural Interstate332201,6261,992,56944,18632,805
Rural arterial466268,1971,023,426117,93518,103
Rural minor arterial543247,028716,9971718,28032,241
Rural major collector1,174342,919499,38613129,74745,295
Rural minor collector23761,56742,247487,9358,272
Rural local road2,704387,223219,83771478,60950,220
Urban Interstate122111,6391,804,893000
Urban freeway/expressway811,06868,609000
Urban other principal arterial79103,136894,27422,76125,236
Urban minor arterial9484,813751,68854,93627,138
Urban collector5533,389178,86641,40314,730
Urban local road6918,56660,90992,2494,943
Total5,8831,871,1698,253,701945158,040258,983

Proposed Bridge Work

Type of WorkNumber of BridgesCost to Repair
(in millions)
Daily CrossingsArea of Bridges
(sq. meters)
Bridge replacement1,106$912594,465253,725
Widening & rehabilitation1$221,635811
Rehabilitation421$281190,358115,352
Deck rehabilitation/replacement49$81133,89133,132
Other structural work615$279234,896114,442
Total2,192$1,5551,175,245517,462

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.