US Bridges

Girder and Floorbeam System bridges

Main girders along the bridge with transverse floorbeams carrying the deck, typical of larger steel bridges. The inventory lists 4,721 of them, 0.8% of all US bridges.

Bridges
4,721
Share of all bridges
0.8%
Poor condition
22.7%
1,070 bridges
Average age
69 yrs
Combined length
381 mi
Oldest
1830

Girder and Floorbeam System bridges by state

StateGirder and Floorbeam SystemShare of state's bridges
Pennsylvania4311.8%
New York3061.7%
Kansas2671.1%
Nebraska2641.7%
California2551.0%
Missouri2421.0%
Ohio2240.8%
Louisiana1811.4%
New Jersey1802.6%
West Virginia1742.4%
Iowa1400.6%
Oklahoma1270.6%
Washington1221.4%
Massachusetts1052.0%
Minnesota980.7%
Oregon871.0%
Maryland811.5%
Montana791.5%
Illinois770.3%
North Carolina770.4%
Colorado750.8%
Wisconsin730.5%
Kentucky710.5%
Michigan710.6%
Alabama710.4%
Virginia680.5%
Mississippi560.3%
Texas520.09%
Indiana510.3%
Idaho501.1%
Vermont461.6%
Arkansas450.3%
Tennessee410.2%
Puerto Rico411.7%
Maine361.4%
Connecticut360.8%
Georgia320.2%
Alaska311.9%
Florida300.2%
New Hampshire301.2%
Arizona300.3%
Wyoming290.9%
District of Columbia238.8%
South Dakota200.3%
Hawaii181.5%
Nevada180.8%
South Carolina180.2%
Utah130.4%
Rhode Island91.1%
North Dakota80.2%
Delaware50.6%
New Mexico50.1%
U.S. Virgin Islands28.3%

Materials used

Steel59.4%
Steel Continuous27.2%
Concrete7.3%
Concrete Continuous2.5%
Prestressed Concrete2.0%
Wood or Timber1.1%

When they were built

<1900: 62 bridges62<19001900s: 160 bridges16019001910s: 168 bridges16819101920s: 375 bridges37519201930s: 748 bridges74819301940s: 336 bridges33619401950s: 708 bridges70819501960s: 709 bridges70919601970s: 594 bridges59419701980s: 287 bridges28719801990s: 228 bridges22819902000s: 129 bridges12920002010s: 142 bridges14220102020s: 75 bridges752020
Girder and Floorbeam System bridges built per decade. Year built as recorded in the inventory; reconstruction years are not included.

Busiest

  1. Interstate 110 over Manchester Ave
    Los Angeles County, California · 300,000 vehicles/day
    Good
  2. State Route 57 over BNSF RY
    Orange County, California · 271,000 vehicles/day
    Good
  3. State Route 57 over BNSF RY Spur Track
    Orange County, California · 271,000 vehicles/day
    Fair
  4. I 80-I 880 Conn over SB 880 I 80 W Grand
    Alameda County, California · 269,472 vehicles/day
    Fair
  5. Southeast Frwy over CSX RR Nj & Va Ave
    District of Columbia, District of Columbia · 252,800 vehicles/day
    Fair

Longest

  1. I0010 over W Atchafalaya Floodway
    St. Martin Parish, Louisiana · 23,440 ft
    Fair
  2. US64 over Croatan Sound
    Dare County, North Carolina · 14,265 ft
    Poor
  3. LA0006 over Toledo Bend Res.
    Sabine Parish, Louisiana · 13,196 ft
    Fair
  4. IH 345 SB over IH 30 US 75 Dart Rail
    Dallas County, Texas · 13,192 ft
    Poor
  5. IH 345 NB over IH 30 US 75 Dart Etc
    Dallas County, Texas · 13,114 ft
    Poor

Oldest

  1. Waterworks Apt RD over Delaware Canal
    Bucks County, Pennsylvania · Built 1830
    Poor
  2. Gravel Pit Road over Delaware Canal
    Bucks County, Pennsylvania · Built 1832
    Poor
  3. KY-3113 over Lee Creek
    Mason County, Kentucky · Built 1835
    Poor
  4. Bulls Bridge Road over Housatonic River
    Litchfield County, Connecticut · Built 1842
    Fair
  5. Iron Bridge Road over Raritan Valley Line
    Hunterdon County, New Jersey · Built 1852
    Fair