The surface of the United States is crisscrossed by 4 million miles of public roads—more than that of any other nation in the world. Roads are an essential part of infrastructure; they allow people, goods, and services to flow quickly and efficiently from one corner of the country to another. Bud Moore, who began a long career with the U.S. Forest Service in 1934, and spent decades cutting roads into the American West, once believed that these incursions also benefited wildlife and wildlands. With better access, “elk could be cared for. Natural stream fisheries could be improved. Log jams could be moved … to create more room for fish to spawn.” Nature was messy, he reasoned; human beings could bring order to it. The environmental journalist Ben Goldfarb shows otherwise in his new book, Crossings: How Road Ecology Is Shaping the Future of Our Planet. Crushing turtles, severing ancient deer migration routes, isolating cougar populations—Goldfarb argues that “there may be nothing humans do that causes more misery to more wild animals than driving.” Even Moore …