Automated vehicles (AVs) have emerged rapidly in recent years, becoming a focus of high expectations and heated debates. Advocates argue that the arrival of AVs will make driving safer, greener, cheaper, and faster, bringing ubiquitous access to transportation while significantly reducing traffic congestion and environmental impacts. Skeptics, in contrast, suggest that the appeal of AVs will induce additional driving, offsetting or even overwhelming the positive effects of increased automation. Many analysts now believe that the solution lies in ensuring that most vehicle trips are shared to serve the same number of passenger miles with fewer vehicle miles, reducing traffic congestion. However, these analyses fail to recognize that reducing congestion will induce yet more demand for driving and attract riders from other transportation modes including public transit, which is already experiencing falling ridership in many cities. In this study, we explore the impact of AVs and pooling on consumer mode choice and the effect on the performance of both road and public transit systems. We show that the well‐intentioned move to promote pooling may have the unintended consequence of triggering a public transit death spiral, leading to both worse public transit quality and more rather than less traffic congestion. We argue that the deployment of AVs and pooling can be effective at accelerating the transition to sustainable urban mobility, but only when accompanied by policies that make driving less attractive, not more.

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The real-world impacts of the Trump administration's effort to roll back the Corporate Average Fuel Economy (CAFE) standards for new light-duty vehicles are not obvious, because new vehicles are highly durable and remain in the on-road fleet for many years. We demonstrate that freezing CAFE between 2020-2026, one of the proposals circulated by the Trump administration, will increase fleet fuel consumption and greenhouse gas emissions until 2040 and beyond, because relatively lessefficient vehicles sold during this time would remain in use for potentially decades. We argue for stringent fuel-economy standards for new vehicles, and for placing greater emphasis on the retirement and disposal of the oldest and most inefficient vehicles on our roads. These steps will help to build a fleet that is efficient, low-emission, and adaptable as the automotive industry enters a period of unprecedented technological change.

Background. A significant gap exists in the United States between ambitious regulatory goals requiring firms to introduce hybrid and electric vehicles, and consumer adoption of these technologies to date. However, the interventions required to close this gap are not obvious due to the complex feedbacks and time delays that govern alternative fuel vehicle (AFV) diffusion. Purpose. The purpose of this article is to introduce Driving the Future (DtF), a free, web-based management flight simulator to explore the effects of automaker strategies and public policies on the US automotive market. Method. We develop a behavioral, dynamic model portraying multiple automobile and fuel types, fueling infrastructure, and consumer choices, enabling users to rapidly experiment with how a wide array of decisions and assumptions shape the dynamics of AFV diffusion out to 2050. Results. We describe how the simulator can be used to explore various scenarios for AFV adoption, and discuss how the simulator can help improve mental models and decision-making. We present evidence from classroom and online experiments, demonstrating that the simulation is both effective in developing users’ understanding of AFV diffusion dynamics, and enjoyable to use.

Achieving societal climate goals requires rapid reductions in greenhouse gas (GHG) emissions from transportation. Recent efforts by policymakers have focused on increasing consumer adoption of electric vehicles (EVs). Nevertheless, EV sales remain low. Worse, even if EV market share jumped dramatically, it would take decades to replace the existing vehicle fleet, during which time vehicle GHG emissions would continue, worsening climate change. Consequently, some argue for policies to accelerate the retirement of inefficient fossil-powered vehicles through "cash-for-clunkers" (C4C) programs. We examine C4C policies through a behavioral model of vehicle fleet turnover and EV market development in the United States. We find C4C policies can substantially reduce vehicle fleet emissions at reasonable cost per tonne of CO 2 . To meet emissions reductions goals, C4C policies should apply only when consumers replace their fossil-powered vehicles with EVs. C4C policies incentivizing EVs accelerate cost reductions through scale economies, charging infrastructure deployment, model variety, and consumer awareness, boosting EV adoption beyond the direct effect of vehicle replacement. The result is a substantial synergy amplifying the impact of C4C and lowering unit cost of emissions reductions. C4C is further amplified when deployed together with complementary policies promoting renewable electricity production and a gas tax or carbon price.