Local governments tried endless variations of asphalt and concrete before developing paving surfaces that didn’t produce excess dust or deteriorate quickly under rain and snow. They gradually built longer bridges, learning from earlier designs that worked, and that didn’t. They tried out different paint colors for lane markings, finding the ones that drivers could see best.
This little-things perspective is needed at a time when America’s infrastructure agenda is simultaneously characterized by grandiose ambitions and limited budgets. Money is tight, and infrastructure needs are going unaddressed. At the same time, despite funding limitations, politicians have a tendency to fall in love with novel, pathbreaking, expensive projects that frequently go astray, resulting in arguments against spending more on infrastructure.
Petroski devotes one chapter of his book to the new eastern span of the San Francisco-Oakland Bay Bridge, which opened in 2013, nine years late and $5 billion over budget. “With uniqueness also come uncertainties — of complications during design and construction and of cost,” he writes. Replacing an old bridge with seismic problems could have been done fairly easily and cheaply by building a simple viaduct. But politicians wanted a “signature span,” and for a variety of aesthetic reasons they chose to build a single-tower, self-anchored suspension bridge — a relatively rare design. The proposed bridge would be the longest of its kind in the world.