Conditions and Performance

Exhibit ES41C: Year of Construction

Exhibit ES41C is a bar graph that shows how many bridges were constructed during five-year intervals over the last century. The vertical axis measures bridges from 0 to 60,000 in increments of 10,000. The horizontal axis has 21 bars with a five-year period for each. The peak period of bridge building was between 1956 and 1970. The first bar indicates that about 10,000 bridges were built before 1900. The second bar indicates that about 1,000 bridges were built between 1901 and 1905. About 4,000 bridges were built between 1906 and 1910. About 4,000 bridges were built between 1906 and 1910. About 3,800 bridges were built between 1911 and 1915. About 9,000 bridges were built between 1916 and 1920. About 10,000 bridges were built between 1921 and 1925. About 22,000 bridges were built between 1926 and 1930. About 26,000 bridges were built between 1931 and 1935. About 31,000 bridges were built between 1936 and 1940. About 10,000 bridges were built between 1941 and 1945. About 27,000 bridges were built between 1946 and 1950. About 32,000 bridges were built between 1951 and 1955. About 52,000 bridges were built between 1956 and 1960. About 57,000 bridges were built between 1961 and 1965. About 55,000 bridges were built between 1966 and 1970. About 43,000 bridges were built between 1971 and 1975. About 38,000 bridges were built between 1976 and 1980. About 37,000 bridges were built between 1981 and 1985. About 42,000 bridges were built between 1986 and 1990. About 40,000 bridges were built between 1991 and 1995. And about 32,000 bridges were built between 1996 and 2000.

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