State spending key to infrastructure operations and maintenance.

Currently, much infrastructure spending is funded and directed by states

Total public spending on transportation and water infrastructure was $416 billion in 2014. Of that total, just 23 percent came from the federal government, with the vast majority—77 percent—coming from state and local governments (CBO 2015).

Historically speaking, state and local governments have consistently taken responsibility for the majority of spending on transportation and water infrastructure but to varying degrees at different times. Figure B shows the percentages contributed by the federal government and by state and local governments to total public spending on transportation and water infrastructure from 1956 to 2014.

Following the passing of the Federal-Aid Highway Act of 1956—which enabled construction of the country’s interstate highway system—the federal government’s role in infrastructure ramped up considerably. In 1956, the federal percentage of public spending on transportation and water infrastructure was 15 percent; by 1960, it was 31 percent. Between 1959 and 1975, the federal share of infrastructure spending averaged 30 percent; that share increased further in 1976, hovering between 35 and 38 percent until 1981, when it began to decline. The federal percentage of spending on transportation and water infrastructure averaged 25 percent between 1987 and 2014; in 2014, it sat at 23 percent.

Behind these numbers lie considerable differences in how the types of transportation and water infrastructure spending are apportioned among different levels of government. Federal government spending leans more heavily toward capital investment; in 2014, the federal government’s share of capital spending was 38 percent. Federal contributions make up a much smaller percentage of spending on operations and maintenance—12 percent in 2014. (Total public capital spending on transportation and water infrastructure was $181 billion in 2014, while total spending on operations and maintenance was $235 billion.) Though state and local governments bear the heavier burden for both types of transportation and water infrastructure spending, they must spend a much larger share of their dollars on operations and maintenance than on capital investments.