LONDON, Ohio (AP) -- Within 24 hours of buying his red Ford Mustang Mach-E, Liam Sawyer set off on a camping trip.

Sawyer, who bought the electric SUV "because I think the technology is cool and the range is just long enough," searched ahead of time for convenient charging stations between his home in Indianapolis and Allegheny National Forest in western Pennsylvania.

About 175 miles (282 kilometers) into his journey, he stopped at a new public charging station at the Pilot Travel Center along Interstate 70 outside Columbus, Ohio. The station, which opened in London, Ohio, in December with four chargers, can power an EV in about half an hour while drivers buy food and drinks and use amenities.

That first charge cost Sawyer, a 32-year-old civil engineer, about $20.

The Ohio charging station was created from the $5 billion National Electric Vehicle Infrastructure program, part of the bipartisan infrastructure bill President Joe Biden signed into law in November 2021. More than two years later, only four states -- Ohio, New York, Pennsylvania and Hawaii -- have opened stations funded by the program.

Biden, a Democrat, has set a goal of creating a national network of 500,000 publicly available chargers by 2030. Easily accessible charging ports are a key part of his effort to encourage drivers to move away from gasoline-powered cars and trucks that contribute to global warming.

That effort took on greater urgency this month as the Biden administration announced new automobile emissions standards that officials called the most ambitious plan ever to cut planet-warming pollution from passenger vehicles. Meeting those standards would require a huge increase in sales of EVs and plug-in hybrids.

EVs hit a record 1.19 million in sales in the U.S. last year and accounted for 7.6% of the total U.S. vehicle market, up from 5.8% in 2022.

Transportation emissions are the nation's largest source of greenhouse gases.

The Biden administration says the federal charging program is on track. Several states, including Maine, Vermont and Colorado, are expected to open public charging stations later this year, while more than a dozen others have awarded contracts for projects or broken ground.

"We are building this national framework from scratch, partnering with states to set plans, and we want to make sure we are taking appropriate care to set this program up correctly,? Federal Highway Administrator Shailen Bhatt said in an interview.

"The first two years were about getting the rules right, getting the plans in place," Bhatt said. "And now what you're going to see is this year being about the chargers coming online."

As part of the national charging station rollout, the Biden administration awarded $623 million in grants to states, local governments and tribes in January. The grants will fund 47 EV charging stations and related projects in 22 states and Puerto Rico, including 7,500 charging ports.

Separately, Walmart and other private companies have pledged to build a network of affordable fast-charging stations for EVs. The federal program is also expected to serve as a catalyst for other projects.

"We're committed to making sure that all Americans can charge (their EVs) where they live, work, shop, play, pray,? said Gabe Klein, director of the Joint Office of Energy and Transportation, which runs the federal charging program.

But even some of the government's own experts say 500,000 public chargers won't be enough to meet Biden's ambitious climate goals. The Department of Energy's National Renewable Energy Laboratory estimated last year that the U.S. will need 1.2 million public chargers by 2030, a huge jump from the 175,00 public charging ports now available, as measured by the Alternative Fuels Data Center, a division of the Energy Department.

The availability of charging stations is key to persuading Americans to buy EVs.

Driving range anxiety is still an impediment, along with cost. About 80% of respondents cited concerns about a lack of charging stations as a reason not to buy an electric vehicle, according to a 2023 survey from The Associated Press-NORC Center for Public Affairs Research and the Energy Policy Institute at the University of Chicago.

Seven in 10 said they would not buy an EV because it takes too long to charge and the battery technology isn't ready.

In some parts of the country -- especially rural areas far from major cities -- "there are definitely corridors where you have worries about range anxiety,'' Bhatt said. "It is going to take longer to get to them, just like it took longer to get cellphone coverage in those places.''

But he said the administration's goal is to have chargers every 50 miles (80 kilometers) along U.S. interstates. Other major charging networks offered by Tesla, EVgo and Electrify America prioritize shopping centers, gas stations and grocery stores, but long-distance travel is where many Americans perceive the biggest gap.

As Biden doubles down on clean energy as part of his reelection campaign, it's notable that Ohio, a swing state led by Republican Gov. Mike DeWine, was one of the first movers in the federal charging endeavor.

"Electric vehicles are the future of transportation, and we want drivers in Ohio to have access to this technology today," said DeWine, who appeared at the Ohio station's grand opening in December.

A state Department of Transportation program, DriveOhio, served as the charging station's organizational structure. A public-private partnership authority helped supply money needed for the project after the federal program contributed 80% of the estimated $500,000 to $750,000 cost, including buildout, operation and maintenance for five years.

"I actually don't think these are moving very slow. I think they're going really quickly given that they're tiny construction projects that we're deploying at a pretty significant scale," said Preeti Choudhary, DriveOhio's executive director. "Getting them in the ground quickly is important because we do have this growing contingency of EV drivers out there and they need to be supported when they're driving across our state or across the country."

Meeting federal requirements and operating standards is a challenge for states with little experience rolling out this type of infrastructure, according to Loren McDonald, an independent analyst tracking the buildout.

"The states are moving at very different speeds," he said. "It might take a good 18 months on average for a lot of these stations to come online.''

Projects can be held up for months to years by delays with permitting, approvals, electrical upgrades and equipment. The latter can be costly. In California, the state with the most electric cars, its Public Utilities Commission could spend $50 billion through 2035 just to meet demand there.

Sawyer, who was charging his Mustang as semi-trucks lined up at rows of gas pumps nearby, said he intends to mostly charge his car at home overnight, but he appreciates the public stations for his occasional road trips. He doesn't mind the half-hour charging time.

"Having the 20 minutes to 30 minutes to kind of rest your feet, get lunch isn't that bad if you're not in a rush,'' he said. "If you have the luxury of time, it's worth it."

"I definitely think the infrastructure needs to get up there more, right?" he said. "And faster charging will come."

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Daly reported from Washington. St. John reported from Detroit.

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