Traffic Operations and Management

Plug-in electric vehicles (EVs) are reshaping the transportation energy landscape, providing a practical alternative to petroleum fuels for a growing number of applications. EV sales grew 55× in the past decade (2014–2024) and 6× since 2020, driven by technological progress enabled by policies to reduce transportation emissions as well as industrial plans motivated by strategic value of EVs for global competitiveness, jobs and geopolitics. In 2024, 22% of passenger cars sold globally were EVs and opportunities for EVs beyond on-road applications are growing, including solutions to...

The purpose of this report is to provide a research-driven analysis of options that can put California on a pathway to achieve carbon-neutral transportation by 2045. The report comprises thirteen sections. Section 1 provides an overview of the major components of transportation systems and how those components interact. Section 2 discusses the impacts the COVID-19 pandemic has had on transportation. Section 3 discusses California’s current transportation-policy landscape. These three sections were previously published as a synthesis report. Section 4 analyzes the different carbon scenarios...

Transportation systems contribute significantly to air pollution and ∼15% globally and ∼25% in the United States to emissions climate-changing gases. In the United States, the Corporate Average Fuel Economy (CAFE) standards for motor vehicles were significantly raised in 2012 for the first time in almost three decades. The standards now call for an average across manufacturers of 54.5 miles per gallon (mpg) for new passenger cars by 2025, or 163 grams per mile (g/mi) of greenhouse gas (GHG) emissions, and of 47 mpg (196 g/mi) by 2021. The light truck standards, which include minivans and...

This paper develops a centralized reinforcement learning (RL)–based controller for Connected and Automated Vehicles (CAVs) operating in mixed autonomy settings designed to lower overall traffic fuel consumption. The traffic dynamics are formulated as a coupled PDE–ODE system, with the PDE governing macroscopic density evolution of the traffic and the ODEs characterizing the motion of CAVs that act as moving actuators. We integrate finite volume numerical schemes with the RL controller as the control input. Numerical experiments demonstrate that the proposed RL controller achieves a lower...