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 realized this toward the end of his life, noting in his 1996 book that “none of us had the wisdom to foresee the consequences.”

Crossings is a follow-up of sorts to Goldfarb’s award-winning first book, Eager. That book focused on the industrious beaver, a creature that fundamentally changes the world around it by constructing dams that can have the unintended but beneficial effect of preventing flash flooding and helping maintain groundwater levels. Goldfarb now turns his attention to another “infrastructure species”: humans.

[Read: America is telling itself a lie about roadkill]

Although scientists have been examining the negative impact of roads since at least the 1920s, only relatively recently, in the 1990s, was the subject given an English name: “road ecology.” Richard Forman, the Harvard ecologist who coined the phrase, defined it as “how life change[s] for plants and animals with a road and traffic nearby.” This is the concept that animates Crossings. Goldfarb expertly researches the history of American roads, shows how the freedom of movement they facilitate became part of the American identity, and outlines the negative and positive ways roads affect both wildlife and humans. Most important, the ideas in Crossings, which Goldfarb examined in a 2019 article for The Atlantic, explore how we can do less harm in the future by rethinking road construction and placement.

The roadkill data that Goldfarb collates from scientific papers, citizen scientists, and state officials are alarming. He writes about roads in North America with nicknames such as “The Meatmaker” and “Slaughter Alley.” On one road by Lake Erie, cars killed almost 28,000 leopard frogs during a four-year period. On another in Manitoba, 10,000 red-sided garter snakes died in a season. Roads are usually built to maximize travel efficiency, and the faster cars can drive, the more destructive the result. Various species respond differently to the threat of an approaching antagonist. Some, such as porcupines and rattlesnakes, are confident in their defensive skills. Instead of scurrying from a road when a vehicle approaches, they stand their ground and brace for a siege. An F-150, however, is intimidated by neither quill nor venom, and its driver may not even notice the creature they obliterated.

Other animals are hardwired to flee only when a predator is sufficiently close. Called a “flight distance,” this is an energy-saving tactic designed to counter a four-legged threat trotting up at five miles an hour or so, not an 18-wheeled one barreling forth at 70. As a result, deer and some birds don’t even try to escape until it’s too late. “Cars hijacked their victims’ own biology,” Goldfarb laments, “subverting evolutionary history and rendering it maladaptive.”

Crossings explains that the ramifications of roads go far beyond skid marks and carcasses: Our roads are changing the molecular composition of wildlife. Cliff swallows nesting under highway bridges in Nebraska may be evolving shorter wings, which one researcher theorizes gives them more maneuverability to avoid vehicles; their less nimble long-winged relatives lie crumpled on the roadside. In areas with high traffic, some species won’t cross highways at all, resulting in genetic isolation. Researchers can look at the DNA of a black bear in Connecticut, or of an Amur tiger in Russia, and know which side of a major road it came from. This isolation can have catastrophic effects: Small wildlife populations are more prone to inbreeding, genetic abnormalities, and extinction. Roads have negative impacts on humans too, reducing walkability in our neighborhoods and increasing stress levels.

Goldfarb writes early on that Crossings is “about how we escape” from this trap, a promise I clung to throughout the book like an overboard sailor might to a capsized ship. However, the hoped-for map turned out to be more like a trail of breadcrumbs. The author’s skill as a storyteller, the inspiring road ecologists he meets, and the flashes of successful mitigations could not mask the predominantly grim subject matter. Goldfarb guides the reader from “massive squishings” of frogs in Oregon to the “bloody carpet” of Tasmanian highways, and signs of optimism come only in fleeting spurts. The Netherlands, for instance, has built a wildlife crossing with a functioning wetland spanning a road, a railroad track, and a sports complex. In 2019, India completed the Kanha-Pench Corridor, which is a road mounted on stout pillars that allows elephants and tigers to continue roaming undisturbed underneath.

[Read: A basic premise of animal conservation looks shakier than ever]

Although drivers can and should take more responsibility for their actions, Goldfarb argues that the onus of wildlife safety should lie at the top—not on drivers like you and me, but on the institutions that cleared wildlands and laid the asphalt to begin with. “What could be more American than blaming deep-rooted problems on individual failings rather than corporate power structures?” he asks. “By all means, slow down at night, brake for snakes, and shepherd salamanders across the pavement. Yet making roads lie lighter on the land isn’t the job of individual drivers any more than swapping out light bulbs will solve climate change. Instead, it’s a public works project.”

The key question Goldfarb seeks to answer in Crossings is not whether roads are inherently good or bad, but how we make them better. China’s ambitious Belt and Road Initiative will eventually link about 70 countries around the world with improved transportation infrastructure—which is an opportunity to build roads and rails that are less damaging to wildlife. Brazil, though not officially a member of the initiative, has received significant infrastructure investments from China. Its government is working with local nonprofits to install canopy bridges across highways in the Amazon to aid safe primate crossings. Elsewhere in that country, the road through Carlos Botelho State Park is closed to regular traffic at night, when most wildlife are active. The design of the road might also play a role in wildlife safety, as it’s filled with rises and turns that inherently encourage drivers to slow down and thus reduces the risk of collisions. Developers around the world should take note.

In his highly influential 1949 book, A Sand County Almanac, the preeminent American conservationist Aldo Leopold introduced the concept of a land ethic. He believed that water, soil, plants, wild animals, and humans are all part of the same community—one that should be guided by mutual respect. “A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community,” Leopold wrote. Against this standard, Goldfarb notes, “roads are the wrongest things imaginable.” He extends Leopold’s idea to advocate for a “road ethic”: A road is good when it works with the land and its inhabitants rather than seeking to conquer them.

For too long, road ecology has been the domain of academics. Researchers have counted the bodies of mammals, birds, reptiles, and amphibians lining our highways for a century; engineers have learned to design mitigations that continually lessen the carnage. But too many of the conversations around road ecology have been confined to the walls of conference rooms or the tight bindings of academic journals. Notably, Crossings is the second mainstream book in as many years to foist the discussion of road ecology on the wider public, after Darryl Jones’s A Clouded Leopard in the Middle of the Road. Beyond the staggering data and the constructive ideas, Crossings is an important book because it is timely: Road ecology is bleeding into the public consciousness at a moment when we can still act on its lessons.