The transportation sector is the largest source of greenhouse gases in the United States. Net-zero goals will demand major strides to decarbonize the sector. Moving forward, Resources for the Future will continue delivering net-zero transportation strategies that spur innovation to drive deployment at scale, through a diverse technology portfolio that includes electric vehicles, fuels, freight, and aviation.
The transportation sector—which includes economic activity from all forms of travel—accounted for 29 percent of total greenhouse gas emissions in the United States in 2019. Over the past 30 years, emissions from the transportation sector have grown by about 24 percent and have become the largest source of greenhouse gas emissions nationally since surpassing power- sector emissions in 2017. Most modes of transportation depend heavily on fossil fuels for energy: passenger vehicles largely burn gasoline, delivery trucks typically use diesel fuel, and aircraft rely exclusively on jet fuel. Each of these fuels is derived from crude oil, causing the transportation sector to be a large source of greenhouse gas emissions.
The Transportation Program at Resources for the Future (RFF) aims to address the current heavy reliance on fossil fuels by exploring net-zero strategies for the transportation sector through technology and policy design. The program primarily will focus on achieving cost-effective decarbonization of both the passenger vehicle fleet and the medium- and heavy-duty fleet, while policies and approaches such as vehicle electrification, building out public charging infrastructure, and efficiency standards will play a significant role in accelerating the transition to a clean transportation sector. Our work in this area also provides an opportunity to identify equitable solutions for transportation challenges that historically have had a disproportionately negative impact on overburdened communities (for related material, listen to my interview on the Resources Radio podcast).
Here’s how we plan to achieve these goals.
We will ramp up our modeling and simulation efforts in the transportation sector, which will help us empirically evaluate policies that promote low-carbon options.
Understanding the effects of different policies on demand, supply, and prices within the transportation sector will be key to ensuring that transportation policies are both cost-effective and environmentally beneficial. To that end, quantitative models and simulations can provide the robust analyses that are needed to help inform policymaking within the field of transportation decarbonization. RFF’s Transportation Program will work to develop these models for use in policy analysis.
We have developed a robust model for light-duty vehicles, which allows us to estimate the impact of policies such as new and used vehicle subsidies, efficiency standards, manufacturing mandates, and more. Our model has been used to analyze electric vehicle policies and subsidies within the Infrastructure and Investment Jobs Act, the Build Back Better Llegislation, and the Inflation Reduction Act; it’s also helped in the context of tightened fuel economy standards. Tightening fuel economy standards will be an important tool to reduce emissions among the remaining gasoline-powered vehicles in the on-road fleet during a transition to electric vehicles. Even after a complete decarbonization of new vehicles, the existing fleet will continue to include gas-powered vehicles for some time. Moving forward, we will continue to leverage the model to help inform policymaking around the decarbonization of personal cars and light trucks.
Credit: Nathalie Lees
Within the truck and bus sector, however, quantitative models and simulations are scarce. This lack of modeling data means that we’re missing information about how trucks are bought, used, and scrapped; how manufacturers choose the price, fuel efficiency, and technology in their vehicles; how policies affect decisions for consumers and manufacturers; and the resulting costs and benefits to society. These unknowns will be an obstacle in cases when the US Environmental Protection Agency sets new emissions standards for trucks, when states debate subsidizing electric charging and hydrogen infrastructure, or when school jurisdictions consider purchasing electric buses. Modeling efforts tend to be scarce because of two related challenges: a lack of data, and limited adoption of new types of vehicles and technologies. Given low adoption rates to date, it’s difficult to estimate future consumer demand for electric trucks and buses and to determine how that demand depends on factors like refueling infrastructure.
We plan to confront these challenges through the development of two models. The first will model the demand and supply of vehicles in the trucking sector, allowing us to estimate the impact of transportation policies on market conditions and environmental outcomes. The second will simulate the effects of electricity tariff structures on electric truck and bus fleets, to better understand how utilities can leverage smart pricing to simultaneously accelerate adoption of these electric vehicles while also reducing environmental and electric grid impacts associated with charging the large batteries in these vehicles.
Distinct from our work to model policy effects on vehicle fleets, we will continue to explore related transportation policies and topics, including biofuels and low-carbon fuel standards, critical minerals, and hydrogen infrastructure.
We will explore options in the transportation sector that can help ensure equity across communities in terms of clean air, access to mobility services, and more.
As the country moves toward a decarbonized transportation sector, ensuring that decarbonization strategies are equitable will be key. The Biden administration’s Justice40 Initiative demonstrates the federal government’s commitment to improving equity in our decarbonization pathway, but the efforts require careful consideration about clean energy investments and the resulting benefits. Looking at the transportation sector, we will explore questions such as: How can electric vehicle charging stations be deployed in a way that ensures access for low-income and disadvantaged communities, while helping accelerate electric vehicle adoption by these households? What are the distributional impacts of decarbonization policies, which will include vehicle efficiency standards, electric vehicle subsidies, and electric vehicle mandates? How will the recent ban on new gasoline vehicles in New York affect emissions in disadvantaged communities?
Credit: pisaphotography / Shutterstock
For example, traffic pollution can negatively affect educational outcomes for students in schools that are located near major roadways and freeways. We’ll develop a high-resolution network of air-quality and weather monitors in New York City, which will allow us to gauge the effects of traffic pollution on the indoor air quality of urban schools and, relatedly, on educational outcomes. We will use these data to provide information to community members about the air quality in their neighborhoods and schools. Furthermore, in the event that we observe indoor air pollution concentration in classrooms that reach levels of concern, we’ll advise the schools on improving indoor air quality based on guidelines from the US Environmental Protection Agency.
We will coordinate with stakeholder groups to produce the most promising and effective solutions for the transportation sector.
Decarbonizing the transportation sector will require coordination among various stakeholders—including vehicle and battery manufacturers, charging station owners, electric utilities, local and federal government, fleets, and communities—to ensure that the transition to a clean transportation sector is cost-effective, equitable, and environmentally friendly. The most effective solutions will incorporate viewpoints and concerns that affect all stakeholders. To that end, RFF’s Transportation Program will host convenings to bring together diverse stakeholders in conversations around the development and implementation of policies that are effective, efficient, and equitable. These convenings will be used to develop recommendations for optimal approaches to decarbonizing transportation.
Getting to a Net-Zero Resilient Economy by Supporting Reduced Emissions and Equity in the Transportation Sector
A growing economy relies on an effective and efficient transportation system—but climate change, pollution, congestion, and safety issues reduce the value of the sector. In the months and years to come, RFF experts will analyze the effectiveness, benefits, costs, and distributional consequences of transportation policies that reduce emissions and positively influence the behavior of consumers and producers.
A version of this article appeared in print in the Fall 2022 issue of Resources magazine.
