The crumbling infrastructure of the United States represents an
opportunity for new types of sensors, inspection equipment and
repair materials. Public (Federal and state) expenditures on
infrastructure have grown by 1.7% per year from 1956 to 2004 and
in recent years, have been growing even more rapidly, rising by
2.1% per year, after adjustment for inflation. This rate of
growth translates into a constant fraction of GDP, about 1% to
1.2%, being spent on infrastructure. The Congressional Budget
Office reported that Federal and state governments spent $67
billion on highway infrastructure and $28 billion on drinking
water and wastewater infrastructure in 2004. The amount of
infrastructure to inspect is enormous, according to a National
Institute of Standards and Technology (NIST) white paper
entitled “Advanced Sensing Technologies and Advanced Repair
Materials For The Infrastructure: Water Systems, Dams, Levees,
Bridges, Roads, And Highways.” The nation has 1,000,000 miles of
water mains, 600,000 bridges, an