ALEXANDRIA, Va.—The United States Postal Service (USPS) will now order twice the amount of electric vehicles than it had originally projected for its new fleet, reports the Associated Press.

USPS plans to purchase 50,000 next-generation delivery vehicles and of those vehicles, at least 50% of them will be electric vehicles. The Post Office’s original plan announced in February would have made 10% of its next-generation fleet electric. In March, USPS upped its EV investment to 20%. The Post Office plans to purchase another 34,500 commercially available vehicles over two years, bringing its total amount of vehicles purchased under its latest proposal to 84,500.

“The Postal Service anticipates evaluating and procuring vehicles over shorter time periods to be more responsive to its evolving operational strategy, technology improvements, and changing market conditions, including the expected increased availability of BEV options in the future,” wrote USPS in a statement.

The Post Office’s initial plan announced in February received criticism from environmentalists and the Biden Administration. The Environmental Protection Agency said the initial plan by the Postal Service, an independent agency, “underestimates greenhouse gas emissions, fails to consider more environmentally protective feasible alternatives and inadequately considers impacts on communities with environmental justice concerns.”

Under the USPS’ latest environmental proposal, the maximum amount of vehicles it can purchase under the Supplemental Environmental Impact Statement is 84,500 vehicles, and of those vehicles, the Post Office said that at least 40% will be EVs. In total, USPS plans to purchase 165,000 next-generation vehicles over a decade.

Environmentalists wanted the Post Office to buy less gas-powered next-generation delivery vehicles. Additionally, 16 states, environmental groups and a labor union sued to stop USPS from purchasing next-generation delivery vehicles under the initial plan because it skewed heavily toward gas-powered trucks.

“Ultimately, the entire postal fleet needs to be electrified to deliver clean air in every neighborhood in the country and avoid volatile gas prices,” Adrian Martinez, senior attorney on Earthjustice’s Right to Zero campaign, told AP. Earthjustice was one of the environmental groups that sued the Post Office.