California Air Resources Board

Our low carbon transportation choices research program seeks to: 1) improve our understanding of household transportation and vehicle choices, 2) understand market forces, consumer acceptance, and real-world emission benefits of new and used plug-in electric vehicles and fuel cell electric vehicles, and 3) increase the adoption of clean vehicles across households of all income levels and optimize equitable distribution and return on investment of clean vehicle incentives.

Find additional information and projects in our research projects catalog.

Complete Research Projects

Examining Factors that Influence ZEV Sales in California (Contract 13-303) California state policies are helping to expand the early plug-in electric vehicle (PEV) market, specifically carpool lane access and purchase rebates.  Higher gasoline prices appear to encourage ZEV sales.

New Car Buyer’s Valuation of Zero-Emission Vehicles (ZEVs) (Contract 12-332) Low awareness and poor knowledge of ZEVs and plug-in hybrid-electric vehicles (PHEVs) are significant barriers to adoption.  But consumers with greater awareness and experience with ZEVs and PHEVs are more likely to value them positively.

Modeling Household Vehicle and Transportation Choice and Usage (Contract 11-322) For Californians who don’t have mobility limitations due to financial constraints or physical disabilities, vehicle ownership and usage decisions are affected by attitudes, lifestyle preference, and residential location, including both neighborhood and regional density and proximity to rail. Households seem to prefer having vehicles of differing fuel economy.

The Dynamics of Plug-In Electric Vehicles (PEVs) in the Secondary Market and their Implications for Vehicle Demand, Durability, and Emissions (Contract 14-316) The early used PEV market appears to be attracting buyers with slightly lower incomes than in the new PEV market. Early used PEV buyers have significant knowledge gaps, which reduce their ability to compare price options. Owners of short-range used PHEVs, and specifically those with about ten miles of electric range, are charging their vehicles less than they could be. Used PEV consumers are highly satisfied. PEV sales to minority groups show no clear signs of market access discrimination through prices paid and distance driven to purchase these vehicles in the new or used PEV markets as compared to those of non-Hispanic whites.

Active Research Projects

Advanced Plug-In Electric Vehicle Usage and Charging Behavior (Contract 12-319) Preliminary results indicate that households maximize the use of their PEVs. Nissan Leaf vehicles were less likely to be driven on days that required charging to complete a day’s travel, whereas PHEVs were more likely to be used as the distance of travel increased. PHEVs with smaller electric range were plugged in less than those with greater range, and the plugging in rate increased with higher gasoline prices. Up to about one-fifth of PHEV engine starts were attributed to high-power cold starts, which emit higher concentrations of criteria pollutants. This study is co-funded by the California Energy Commission.

Emerging Technology Zero Emission Vehicle Household Travel and Refueling Behavior (Contract 16RD009) This project will quantify emission benefits from real-world use of emerging technology vehicles including both PEVs and fuel cell electric vehicles.

Designing Light-Duty Vehicle Incentives for Low- and Moderate-Income Households (Contract 15RD011) This project seeks to understand vehicle purchase and retirement decisions in low- and moderate income households in order to promote the retirement of functional, high-emitting vehicles and increase the adoption of advanced clean vehicles in low- and moderate-income households.

Additional Resources

• CARB Land Use and Transportation Research
• Clean Vehicle Rebate Project
• Enhanced Fleet Modernization Program Plus Up Pilots
• Statewide vehicle and emission inventories
• California Fuel Cell Partnership
• PEV Collaborative
• Veloz
• The California Energy Commission’s Transportation Energy Research
• EV Explorer
• The International Council on Clean Transportation