Highway construction is a very big business. Nationally, the United States spends nearly $150 billion per year on road and highway construction, an amount that has increased by almost 50 percent in the past five years. The highway-building bureaucracy has created a powerful and well-organized political machine that mobilizes construction companies, engineering firms, truckers, and local business boosters. Politicians are always keen to take credit at ribbon-cuttings. Highway departments routinely shortchange maintenance to cobble together funding for massive empire-building highway and bridge projects.

In pursuit of these goals, highway agencies depend on traffic models. These models are bewilderingly complex, their results are offered with false certainty, and when they are challenged in court, judges routinely defer to “agency expertise.” To understand how these impenetrable models work, let alone contest their accuracy or validity, is a daunting task. The models thus serve as powerful technocratic weapons in securing funding, dismissing environmental concerns, and blocking outside scrutiny. Concrete keeps pouring into new highway lanes, regardless of their utility for drivers or their damage to the world around them.