National Bridge Inventory: Alaska



  • Of the 1,592 bridges in the state, 155, or 9.7 percent, are classified as structurally deficient. This means one of the key elements is in poor or worse condition.
  • This is up from 150 bridges classified as structurally deficient in 2014.
  • 12 of the structurally deficient bridges are on the Interstate Highway System.
  • 144 bridges are posted for load, which may restrict the size and weight of vehicles crossing the structure.
  • The state has identified needed repairs on 306 bridges at an estimated cost of $148.7 million.
  • This compares to 315 bridges that needed work in 2014.

County Year Built Daily Crossings Type of Bridge Location
Ketchikan Gateway 1957 15,147 Urban minor arterial South Tongass Hwy over Hoadley Creek
Ketchikan Gateway 1955 12,481 Urban minor arterial South Tongass Hwy over Water St Viaduct
Fairbanks North Star 1953 8,593 Urban minor arterial Wendell Avenue over Chena River (Wendell)
Anchorage 1966 6,768 Rural Interstate Seward Highway over Portage Creek No 1
Ketchikan Gateway 1975 6,277 Urban minor arterial North Tongass Hwy over Ward Creek
Fairbanks North Star 1953 5,325 Urban minor arterial Minnie Street over Noyes Slough (Minnie St)
Anchorage 1966 5,205 Rural Interstate Seward Highway over Virgin Creek
Anchorage 1966 5,205 Rural Interstate Seward Highway over Glacier Creek
Anchorage 1967 5,205 Rural Interstate Seward Highway over Twenty mile River
Anchorage 1966 5,205 Rural Interstate Seward Highway over Peterson Creek
Anchorage 1966 4,265 Rural Interstate Seward Highway over Placer River Main Cross
Anchorage 1967 4,265 Rural Interstate Seward Highway over Placer River overflow
Kenai Peninsula 1959 3,518 Rural arterial Sterling Highway over South Fork Anchor River
Fairbanks North Star 1960 3,488 Urban collector Aurora Drive over Noyes Slough (Aurora)
Matanuska-Susitna 1962 3,196 Rural Interstate Parks Highway over Sheep Creek
Kenai Peninsula 1965 2,116 Rural arterial Seward Highway over Snow River Cntr Channel
Kenai Peninsula 1965 2,116 Rural arterial Seward Highway over Snow River West Channel
Fairbanks North Star 1965 1,932 Rural major collector Chena Hot Spr Rd over Jenny M Creek
Kodiak Island 1980 1,886 Rural major collector Chiniak Highway over Russian River
Yukon-Koyukuk 1958 1,877 Rural Interstate Parks Highway over Little Goldstream Ck
Matanuska-Susitna 1961 1,657 Rural Interstate Glenn Highway over Kings River
Prince of Wales-Outer Ketchikan 1985 1,585 Rural major collector Craig/Klawock/Holl over Crab Creek Culvert
Kenai Peninsula 1949 1,349 Rural minor collector Old Sterling Hwy over Anchor River
Valdez-Cordova 1954 1,315 Rural major collector Copper River Hwy over Eyak River
Valdez-Cordova 1974 974 Rural Interstate Richardson Highway over Gulkana River
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 153 150,531 809,127 12 11,388 44,180
Rural arterial 104 59,765 150,181 5 3,985 9,662
Rural minor arterial 67 29,367 77,297 3 919 1,096
Rural major collector 226 123,812 127,419 19 9,862 10,668
Rural minor collector 76 22,313 27,898 9 1,570 2,423
Rural local road 713 106,713 41,087 86 14,287 1,517
Urban Interstate 46 41,670 1,223,307 0 0 0
Urban freeway/expressway 0 0 0 0 0 0
Urban other principal arterial 59 88,104 1,215,712 0 0 0
Urban minor arterial 52 77,353 444,806 5 10,493 47,823
Urban collector 46 26,673 103,979 5 1,533 5,011
Urban local road 50 17,489 26,219 11 5,122 1,874
Total 1,592 743,788 4,247,032 155 59,158 124,254
Type of Work Number of Bridges Cost to Repair
(in millions)
Daily Crossings Area of Bridges
(sq. meters)
Bridge replacement 69 $79 32,375 21,091
Widening & rehabilitation 1 $0 4,921 111
Rehabilitation 123 $64 122,536 53,349
Deck rehabilitation/replacement 0 $0 0 0
Other structural work 113 $5 11,451 19,567
Total 306 $149 171,283 94,118

About the data:

Data from the Federal Highway Administration (FHWA) National Bridge Inventory (NBI), released March 15, 2019. 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 2017 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 cost estimate is supplied by the bridge owner or the bridge is classified as structurally deficient.

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.

14
from 11 in 2017

in the nation in % of structurally deficient bridges

1. Rhode Island 23.1%
14. Alaska 9.7%
15. Mississippi 9.4%

45
from 46 in 2017

in the nation in # of structurally deficient bridges

1. Iowa 4,675
44. Rhode Island 180
45. Alaska 155
46. Arizona 150
Full State Ranking

  • Source: Bridge data is from the 2018 National Bridge Inventory ASCII files, released by the Federal Highway Administration on March 14, 2019. Note that specific conditions on bridges may have changed as a result of recent work. 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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