Vehicles in the U.S. have gotten much larger over the past few decades, and research suggests that this shift has had far-reaching consequences, making roads more dangerous for everyone while increasing emissions and other environmental impacts. A recent New York Times analysis estimates that between 200 and 400 pedestrian deaths each year could have been avoided if cars had remained roughly the same size as they were 25 years ago. While the rise of SUVs and pickup trucks is often treated as the result of a cultural shift or consumer preference, researchers argue that policy has also helped shape today’s vehicle market. If policy helped encourage this shift, it could also help reverse it.
Research
‘Just one more lane’ still emphasized in transportation engineering textbooks
Modern state DOTs and their engineers are grappling with a different set of challenges than they did in the 20th century. Some are shifting to managing travel demand and limiting vehicle-miles traveled (VMT) to make their systems operate more efficiently. But engineering education programs may not be properly preparing engineers for these new challenges, sometimes leaving them to learn on the job in environments that can be mired in old ways of thinking.
People cross the street where it makes sense
A new study out of Milwaukee highlights a major blind spot in how we approach safety for people on foot. People don’t only cross at intersections; midblock crossings are more common than transportation agencies typically measure and plan for. About one in six crossings in the study happened midblock, sometimes more often than at intersections themselves. This behavior is predictable, widespread, and largely missing in how we design our streets.
States DOTs can lead in cutting emissions. Our latest report explains how.
More states are now tracking harmful carbon emissions, setting ambitious goals to reduce those emissions, and exploring opportunities to meet those goals, even as the federal government walks back its commitment to public health and well-being. With transportation accounting for around 30% of emissions, more than any other sector, state DOTs play a key role. Several states—California, Colorado, Minnesota, Oregon, and Washington—have set an early example of what’s possible.
Addressing the rise in drunk driving requires a systemic approach
Human behavior is one of the biggest wildcards in preventing traffic deaths and serious injuries. That is why many transportation professionals now focus on designing systems that stay safe even when people inevitably make mistakes. Alcohol impaired driving is once again on the rise in the United States, and decades of awareness, education, and enforcement have not solved this problem. New research shows that alcohol is involved in nearly one-third of all traffic deaths, even as public concern about the issue remains very high. In other words, people know drunk driving is dangerous, but some do it anyway. This is not about excusing impaired driving but about acknowledging reality and designing transportation systems that reduce harm when risky behavior persists.
One year into congestion pricing, every DOT can learn from New York City
New York City shares many of the same goals as state and local transportation agencies: cutting traffic, improving travel times, making roads safer, and improving quality of life. Yet decades of investment in highway capacity have failed to deliver on those goals. Commute times have increased 7.5% since 2010, congestion has reached an all-time high, and U.S. roadways have become more dangerous than those of any other wealthy nation.
New research shows where low stress streets make the biggest difference
Making streets less stressful for walkers and bikers is strongly associated with more walking and biking, and new research from Maryland helps clarify where those effects are most pronounced. Building on prior research showing that lower-stress street environments are linked to more walking and biking, this study found that reducing traffic stress has the biggest impact for shorter trips and in places where alternatives to driving already exist. for shorter trips and in places where alternatives to driving already exist.
Building more EV chargers is great. They also need to work
As state DOTs continue to build out an extensive network of electric vehicle chargers, those chargers also need to work consistently. Charging reliability isn’t always fully in a DOT’s control, and many agencies have only recently taken on responsibility for charging infrastructure. Even so, DOTs can still adopt a “fix it first” approach, as some do with their roadways, prioritizing keeping chargers functional as they develop their public networks. Doing so can accelerate the transition to electric vehicles, often a key piece of DOT sustainability goals and climate targets.
We don’t need to overthink induced demand to act on it
The concept of induced demand is now widely recognized in transportation. But we often treat it as a technical modeling issue rather than a basic principle of how people respond to the world around them. Build for cars, and you’ll get more driving; build for transit or biking, and you’ll get more of those too. Shifting the conversation in that direction can improve near-term decisions and strengthen communication between transportation professionals and the public.
To reduce traffic, DOTs need both “carrots” and “sticks”
Nearly every state DOT is grappling with how to reduce traffic and carbon emissions—many states developed official , and congestion relief is often at the top of a DOT’s priority list. But a new study from Swedish researchers says that some of the most common ways to address these challenges—using only “carrots” rather than “sticks,” in the researchers’ words—may leave states struggling to achieve their goals.