By Ryan Warsing, Jackie Lombardi, Miguel Moravec, and Drew Veysey
For decades, the American transportation landscape has been defined by a single, unyielding narrative: the primacy of the personal automobile. While the United States has made significant strides in vehicle electrification, a crucial piece of the climate puzzle remains neglected. State departments of transportation (DOTs), the primary architects of our nation’s infrastructure, have largely focused on expanding road capacity to combat congestion. However, the data is clear—this approach is failing. To achieve climate goals and improve public well-being, states must pivot from a "road-first" mentality to one that prioritizes equitable mobility choices and a reduction in vehicle miles traveled (VMT).
The Main Facts: The Illusion of Road Expansion
The status quo in American infrastructure investment is built on a fundamental misunderstanding of traffic dynamics. Despite billions of dollars poured into highway expansions, congestion persists, and, in many cases, worsens. This phenomenon, known as "induced demand," ensures that when you build more road space, more people choose to drive, quickly filling that space and returning traffic to previous levels.
State DOTs are currently standing at a crossroads. Armed with historic levels of federal funding from the 2021 Bipartisan Infrastructure Law (BIL), these agencies have the resources to reshape the American landscape. Yet, most have chosen to continue the status quo, funneling the vast majority of these funds into highway expansions that lock in decades of future emissions and maintenance liabilities. This path is not only environmentally damaging but also fiscally unsustainable.
A Chronology of Car Dependency
To understand how we arrived at this impasse, one must look at the evolution of American policy over the last half-century.
The Mid-20th Century: The Rise of the Highway Era
Following the post-WWII boom, the United States embarked on the construction of the Interstate Highway System. This period solidified the "car culture" that now dominates our urban development patterns. Zoning laws were rewritten to mandate parking, and investment was systematically diverted away from public transit and toward expansive, sprawling road networks.
The Turn of the Century: Stagnation and Pollution
By the early 2000s, it became evident that the transportation sector was the primary driver of US climate pollution. Despite advancements in fuel efficiency, total emissions from the sector only saw meaningful declines during economic recessions or the global standstill of the COVID-19 pandemic. By 2019, cars and trucks were responsible for 23 percent of US greenhouse gas emissions—a figure that climbs to nearly 40 percent when accounting for fuel production and the "embodied carbon" of vehicle manufacturing.
2021 to Present: The Bipartisan Infrastructure Law (BIL)
The passage of the BIL provided a unique, once-in-a-generation opportunity to correct course. However, early data indicates that states are repeating past mistakes. While the law provides the flexibility to invest in transit, bike lanes, and "complete streets," the majority of funds are still being earmarked for traditional roadway capacity projects.
Supporting Data: The Case for Reduced VMT
The math behind reducing VMT is compelling. RMI’s analysis reveals that by 2050, a 20 percent decrease in national VMT per capita would result in:
- Safety: Avoiding up to 6,000 annual fatalities from traffic collisions.
- Economic Relief: Saving $259 billion annually in vehicle fuel and maintenance costs.
- Climate Impact: Preventing 2.3 gigatons of CO2 equivalent—a reduction equal to shutting down all US emissions for roughly four months.
Even with aggressive electrification, the U.S. cannot meet its climate targets through electric vehicles alone. Because automotive stock turnover is slow and battery supply chains are under immense pressure, reducing the number of miles we drive is the most efficient way to lower the "pollution floor."
Furthermore, the "bloat" of the modern American fleet—where SUVs and crossovers are becoming heavier and more lethal to pedestrians—has offset the gains made by engine efficiency. Research shows that if vehicle weight had remained stable since 2010, the rate of pollution decline would have been 30 percent higher.
Official Responses and Policy Hurdles
The push for change is meeting stiff resistance at the state level. Currently, 23 states have constitutional amendments or legal barriers that prevent gas tax revenues from being used for anything other than road construction. This effectively handcuffs local planners who wish to invest in buses, light rail, or cycling infrastructure.
Furthermore, the federal government has historically provided subsidies that mask the true cost of driving. Gas taxes, tolls, and registration fees have historically covered only 60 to 70 percent of roadway expenditures. The remainder is subsidized by taxpayers—including those who do not own cars.
The "Fix-It-First" Approach
Policy experts and advocacy groups are now calling for a "fix-it-first" mandate. This approach would require states to prioritize the repair of existing, crumbling infrastructure before breaking ground on new, expensive, and often unnecessary highway expansions. By shifting the focus to maintenance and active transportation, states can stop the cycle of increasing debt and environmental degradation.
Global and Local Success Stories
We do not need to reinvent the wheel to find solutions. Paris, France, has achieved a 45 percent reduction in driving since 1990 by installing protective bollards, expanding cycling networks, and prioritizing pedestrian space. Closer to home, Seattle successfully reduced per-capita VMT by 17 percent between 2005 and 2018 by incentivizing remote work, carpooling, and transit-oriented development.
The rapid rise of e-bikes offers another path forward. Between 2019 and 2022, e-bike sales surged by 269 percent in the United States, and they now outsell electric cars. By subsidizing these micro-mobility options, states can provide affordable, efficient transportation that reduces the need for heavy, expensive electric SUVs.
Implications for the Future
The implications of continuing our current path are dire. Beyond the environmental catastrophe, we are locking ourselves into a system that forces low- and middle-income families to spend a disproportionate share of their earnings on car ownership—money that could otherwise go toward rent, healthcare, and education.
Conversely, the benefits of a shift are profound. Investing in greenways, sidewalks, and bike facilities has been proven to create more jobs-per-dollar than traditional highway projects. The Southern California Association of Governments found that for every dollar spent on pedestrian and biking infrastructure, $5.20 in economic value is added to the regional economy.
A Final Reckoning: The 2024 Deadline
A new rule from the US Department of Transportation now requires state DOTs to measure and set pollution reduction targets for their highway systems. The first targets are due in early 2024. While these targets lack federal enforcement penalties, they provide a crucial "sunlight" mechanism. For the first time, the public and advocacy groups will have a standardized metric to hold their state agencies accountable.
The question remains: will state DOTs continue to prioritize the expansion of roads that no one wants and the environment cannot afford? Or will they embrace a future where mobility is defined by choice, equity, and health? The funding is there. The technology is there. The only thing missing is the political will to pivot.
The era of "drive more, live less" is unsustainable. It is time for state leaders to recognize that the most effective way to improve transportation is not to build more lanes for cars, but to build more options for people. By investing in the human-centric infrastructure of tomorrow, we can secure a cleaner, safer, and more prosperous future for all.
