In the suburbs of Des Moines, Iowa, yellow diggers slowly knock chunks out of a tired-looking bridge. Beneath lies Interstate 80, one of America’s economic arteries, which traces the route of the Lincoln highway—the first road to cross America—from New York to San Francisco. The bridge impedes traffic both on the highway—it is too low—and over it—it is too narrow. Its replacement will be a third wider, making room for cycle lanes and more traffic, and six inches higher, allowing bigger lorries to pass beneath. The diggers are out across Iowa, which embarked on a five-year programme to upgrade its bridges and highways in January.

Elsewhere, however, the diggers sit idle. America’s government invests much too little in infrastructure. A study in 2013 by the American Society of Civil Engineers claimed that additional spending of $1.6 trillion, in 2010 dollars, is needed by 2020 to bring the quality of the country’s infrastructure up from “poor” to “good”. Roads are a particular problem: over the past decade, America’s roads have fallen from seventh to fourteenth in the World Economic Forum’s rankings of the quality of infrastructure. Part of the problem is that the federal tax on petrol (gasoline), which provides most of the funding for federal spending on roads, has been stuck at 18.4 cents per gallon since 1993. Over that period the price of construction materials and the wages of construction workers have both risen by more than 75%.

Read the full article on The Economist website.