On June 27, 2019, the California Air Resources Board (CARB) approved a rule requiring the gradual transition of fixed-route airport shuttles into 100 percent zero-emission vehicles (ZEV) by 2035. Applied to public and private shuttles that serve the state’s 13 largest airports, including rental car agencies, hotels, and parking facilities, the regulation was approved with an expectation to reduce greenhouse gas (GHG) emissions by at least 500,000 metric tons. According to CARB, the regulation will also benefit shuttle fleet owners through an estimated $30 million in reduced fuel and maintenance costs. Currently, six airports and private businesses serving nine airports already have zero-emission shuttles operating in the state. This new rule presents “a great opportunity for showcasing this process,” stated CARB Executive Officer, Richard Corey. CARB states that airport shuttles are well-suited to zero-emission technology because they operate on short, fixed routes up to 200 miles per day with low average speeds in a stop/go pattern. When operating in this manner, ZEVs are advantageous from an energy and fuel efficiency perspective. The rule will require annual reporting of vehicles to CARB in 2022, and end in 2035 with full compliance of ZEV airport shuttles.