Zero-emission vehicles are a central component of plans to eliminate greenhouse gas emissions from California’s transportation sector. Because these vehicles generally have higher purchase prices than conventional vehicles and represent a new technology that many households are hesitant to adopt, it is important to find ways to incentivize the adoption of these vehicles. A range of methods have been tested globally, including monetary incentives and stickers that allow these vehicles to access high-occupancy vehicle lanes. This report assesses the potential use of express lane discounts as a driver of ZEV adoption by testing the effectiveness of a range of discount scenarios. These scenarios are built upon a baseline scenario that incorporates adoption drivers from existing policies and market growth trajectories. This analysis treats the express lane discount as a monetary incentive. The researchers find that providing even very large discounts for express lane usage to zero-emission vehicles would only slightly increase vehicle sales but would make these lanes much less capable of serving their other purposes. As part of this project, an Excel tool was developed that allows users to test their own scenarios. As an alternative to providing toll discounts to owners of new zero-emission vehicles, the authors recommend developing targeted incentives that focus on low-income and disadvantaged communities and are available to households that purchased pre-owned vehicles.

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Over the last six years, from 2016 through 2021, a wave of new federal, state, and local funding has supported carsharing services that use electric vehicles and install electric vehicle chargers to reduce greenhouse gas emissions (GHGs) and address climate change. In addition, many of these same funding programs allow support for the location of services in underserved communities with fare levels that enable community members to access these services. This study first explores the potential climate change benefits for carsharing services and the need for these services in underserved areas by reviewing the available published literature. Next, the study discusses the evolution of carsharing in the U.S., including non-profit, for-profit, and recent government-funded carsharing, drawing on published reports, newspaper articles, and expert interviews. Finally, the authors draw conclusions of relevance for future government-funded carsharing programs.

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Carsharing, in which members have access to a network of shared vehicles for short-term rentals, has existed in the US for more than two decades. Within the last six years though, carsharing services have proliferated under a wider variety of business models. These programs are increasingly seen as a means of increasing transportation access in underserved communities—particularly in those with limited public transit service. The recent incorporation of electric vehicles in carsharing programs is also seen as a promising public policy for reducing greenhouse gas emissions. Government support for carsharing has accelerated, with state and federal agencies investing millions of dollars in support of equity and sustainability goals.

As funding grows, it becomes increasingly important to learn from carsharing services that have already been implemented. Researchers at the University of California, Davis and the non-profit organization Mobility Development reviewed evaluations of the travel, emissions, and equity effects of past US carsharing programs and analyzed the evolution of carsharing and its various business models. The aim of the research is to inform the design of and improve the value of investments in future electric carsharing programs, and this policy brief summarizes these findings and provides policy implications.

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