U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
Conditions and Performance
Status
of the Nation's Highways, Bridges, and Transit:
2002 Conditions and Performance Report
|
Exhibit 11-33:
Year of Construction and Cumulative ADT - Deficient Prestressed Concrete Superstructure Bridges
Exhibit 11-33 is a bar graph that shows the year of construction and cumulative ADT for deficient prestressed concrete bridges. The vertical axis measures number of bridges from 0 to 18,000 in increments of 2,000 bridges. The horizontal axis has 10 bars, one for each 5-year period between 1951 and 2000. Each bar has three parts, measuring the distribution of functionally obsolete, structurally deficient, and non-deficient prestressed bridges. From 1951-55, half of the Nation's 800 or so prestressed bridges were structurally deficient and half were non-deficient. From 1956 to 1965, about three-fifths of the Nation's new prestressed bridges were non-deficient, less than one-fifth was structurally deficient, and more than one-fifth was obsolete. After 1966 fewer and fewer new prestressed bridges were deficient-one-quarter in 1970, one-sixth in 1975, one-eighth in 1980, and so on until virtually none were deficient after 1991. There are three other items and a second vertical axis (measuring percentages from 0 to 100 in increments of 10 percent) in this chart. A line, representing the "linear" percent of deficient prestressed bridges for each year of construction by ADT, starts in 1950 at about 30 percent and drops in a straight line to 20 percent by 1975, 10 by 1990, and just over 0 by 2000. A series of small squares, representing the percent of deficient prestressed bridges for each year of construction by ADT, follows the line almost identically, give or take 1 to 10 percentage points. And a series of small triangles, representing the percent of deficient prestressed bridges for each year of construction by numbers, copies the path of the squares almost identically.
Source: National Bridge Inventory.
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Page last modified on November 7, 2014
