US infrastructure spending as a proportion of GDP is at a low not seen since WWII, and that's why America's bridges, dams, roads, power plants and other key infrastructure are such easy fodder for Hurricane Harvey (and the impending Irma devastation). Trump's plan for infrastructure spending is a "ludicrous patchwork of tax breaks and privatizations" that will do nothing to solve the problem.
Here are the graphs — the first, net public (meaning by federal, state, and local government) as a percent of GDP since 1950. I started the graph in 1950, even though the figures begin in 1929, because the extreme values of the Great Depression and World War II years would distort the scale dramatically. The second presents the averages by decade. As the graphs show, net public investment is in a long downtrend and is now at near-record-low levels. The only years with lower levels were 1942–45, when the civilian economy was starved to fund the war effort.
Net civilian investment was 0.5% of GDP in 2016; preliminary numbers for 2017 suggest it hasn't budged. It declined during the Great Recession and its aftermath, and is now less than half 2007's 1.2%. The contrast with the Great Depression is stark. Net civilian public investment rose from 1.9% of GDP in 1929, the year of the crash, to 3.2% ten years later. For the full decade of the 1930s, it averaged 2.6% — the same as the 1960s, a time of dramatic expansion in the public sector. Since then, it's been mostly downhill.
To get back to that 2.6% average would mean an increase of $400 billion a year in public investment. (For details on the shortfall, and where the spending needs to be directed, see the American Society of Civil Engineers' annual report on the topic.)
Why the United States Is Falling Apart
(via Naked Capitalism)