It follows a memorandum of understanding signed by California, Connecticut, Maryland, Massachusetts, New York, Oregon, Rhode Island and Vermont last October, who together account for 28% of car sales in the USA.

The 11-year plan was set out based on shared information from from state regulators, the automotive industry and infrastructure developers, and is aimed at radically increasing take-up of the technology, which includes plug-in hybrids and hydrogen fuel cell vehicles as well as pure EVs.

As of April this year, 200,000 of these vehicles are registered in the United States, of which half have been registered since the memorandum of understanding was signed last October.

Participants will now undertake a wide-ranging campaign to promote electric vehicle usage among fleets and private users, including print and digital marketing and establishing or furthering incentives for purchase, both financial and in terms of ease of usage, such as discounted parking and tolls.

Each state will increase the use of electric vehicles on its own fleet and set standards for charging stations and signage, while helping the used market to stabilise.The Multi-State ZEV Action Plan also sets out priorities to improve infrastructure in company car parks, universities, hospitals and public transport hubs, and make it easier for drivers to access charging points and to pay for the energy used as they would a liquid fuel.