New Study Says Behavioral Science-Based Interventions Improve EV Charging Habits, Reducing Carbon Emissions

On September 16, 2025, the Toyota Research Institute (TRI) shared new research that demonstrates how behavioral science can play a powerful role in improving electric vehicle (EV) charging habits and reducing carbon emissions. The findings come from studies conducted in both the United States and Japan and centered around ChargeMinder, a prototype app developed by TRI’s Human-Centered Artificial Intelligence (HCAI) division. ChargeMinder was built to explore how human behavior, nudges, and timely reminders can unlock the full climate potential of EVs.

The research makes clear that technology alone cannot achieve the maximum environmental benefits of electrified transportation. While plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEVs) are designed to cut emissions, their effectiveness depends heavily on when and how they are charged. If drivers do not plug in consistently, or if charging happens at times when electricity is generated from fossil fuels, the overall reduction in carbon impact is limited. By shifting habits toward regular charging and aligning those charging sessions with times when renewable energy is most available, the impact of each vehicle grows significantly.

“Technology is not the only way to reduce emissions — people’s choices matter too,” said Dr. Gill Pratt, Chief Scientist for Toyota Motor Corporation and CEO, Toyota Research Institute. “This research and development shows how science-based behavioral interventions can both help us reduce carbon emissions as much as possible, as soon as possible, and increase customer satisfaction.”

In the U.S., TRI found that behavioral interventions improved charging frequency by 10 percent among PHEV drivers. In Japan, PHEV and BEV drivers responded by shifting their charging sessions into periods of higher renewable energy production, with a 59 percent increase in charging during those hours. This translated into nearly 30 additional minutes of daytime charging per vehicle, per day. Beyond the climate benefits, the interventions also boosted driver satisfaction. In the U.S., PHEV drivers reported a 16-point increase in satisfaction, reaching 100 percent. These results highlight that well-designed behavioral strategies not only help the planet but also enhance the ownership experience.

“Behavioral science is a powerful, scalable tool to help achieve carbon neutrality,” said Dr. Laura Libby, Manager, Carbon Neutrality, Human Centered Artificial Intelligence, Toyota Research Institute. “Research in behavioral science shows that small, targeted interventions can have a large impact on people’s decisions and actions. Furthermore, compared to other causes of behavior change such as public charging infrastructure initiatives and consumer financial incentives, behavioral interventions are inexpensive and can be deployed quickly.”

ChargeMinder itself applies insights from behavioral science to encourage better charging behavior. It delivers reminders at carefully chosen times, a tactic that laboratory studies show can be up to 50 percent more effective than generic prompts. It reinforces positive behavior with progress streaks, summaries, and encouraging messages that make drivers feel accomplished for building good habits. It also offers educational quizzes, designed using principles from memory science, to help drivers better understand the climate impact of their charging choices in an engaging way. Together, these features represent more than a dozen tailored interventions that can be surfaced through the app or via mobile push notifications.

The app is designed to integrate with vehicle telematics and charging location data in a way that is both secure and anonymous. This capability makes it possible to create personalized experiences for each driver, adapting interventions to their behavior and preferences, while also enabling advanced data analytics to measure the effectiveness of different strategies without compromising privacy. TRI sees this as a critical piece of the puzzle, since personalization is often the key to long-term behavioral change.

Looking ahead, TRI and Toyota’s Carbon Neutral Center plan to expand the ChargeMinder research program to focus on even more personalized and data-driven approaches. By doing so, they aim to help drivers develop more consistent and climate-conscious charging habits that align with Toyota’s broader carbon neutrality strategy. These efforts reflect Toyota’s belief that technologies addressing how people think, feel, and behave will be central to achieving a lower-carbon future.

Since its founding in 2016, TRI has focused on research that amplifies human ability and makes life safer and more sustainable. Led by Dr. Gill Pratt, TRI’s team of researchers is advancing work in automated driving, energy and materials, robotics, human interactive driving, and large behavior models, all with a human-centered AI perspective. With offices in Los Altos, California, and Cambridge, Massachusetts, TRI continues to demonstrate how combining technology with human insight can accelerate the transition to sustainable mobility.