The Tappan Zee Bridge that currently spans the Hudson River isn’t your average crossing. When it opened in 1956, it was a marquee connector that helped complete the 496-mile New York State Thruway, then the state’s largest post-war achievement and a sprawling monument to its evolving suburban identity. Within 40 years, the bridge had become known for another distinction: congestion. By the 1990s, it was carrying 150,000 vehicles each day — 50 percent more than its capacity — and people had begun to talk about replacing it, with plans for multi-billion-dollar rebuilding coming out of Albany. Nearly 300 public meetings and $88 million later, the state had a pretty good idea of what it needed to do — build a bigger bridge with mass transit facilities. Then, with a short press release and a quick news conference, everything changed. In October of 2011, Gov. Andrew Cuomo and the New York State Thruway Authority unceremoniously scrapped more than a decade of studies and community planning in favor of a fast-tracked bridge plan without a new mass-transit component or broader corridor improvements. In a comprehensive telling of this costly state planning debacle, journalist Graham T. Beck explains how the Tappan Zee’s undoing reflects trends in infrastructure development that threaten to undermine the country’s movement toward sustainability.