An infrastructure spending deal crafted by a bipartisan group of senators would represent among the biggest federal investments in rail and transit, the White House said, with spending that could serve the administration’s climate and racial equity goals. But the president also agreed to dramatically pare back a proposed fund to remove or redesign urban highways while cutting investments in electric vehicles.

The agreement includes $312 billion dedicated to transportation, a proposal that would represent a significant boost in federal spending on the nation’s transportation infrastructure. Layered on top of current federal spending, it would provide billions more than lawmakers have included in transportation funding bills moving through Congress, even though it’s scaled back by about one-third from the White House’s initial American Jobs Plan.

Despite the lower overall spending, the administration said it would achieve many of the same transportation objectives.

“This is a big deal for transportation infrastructure, climate action, equity, job creation, and more — it represents a key part of the president’s economic agenda, with major and much-needed investments in America’s future,” Transportation Secretary Pete Buttigieg said in a tweet.

The White House said the plan would “improve healthy, sustainable transportation options for millions of Americans by modernizing and expanding transit and rail networks across the country, while reducing greenhouse gas emissions.” The administration said spending on roads and bridges would come with a focus on reducing the impact of climate change and ensuring the safety of drivers, pedestrians and cyclists.

The agreement calls for $109 billion for roads, bridges and major construction projects, along with $49 billion for transit and $66 billion for rail. The package also would include $25 billion for airports and $16 billion for seaports and waterways — figures that are in line with Biden’s original pitch.

On some specific equity and climate measures, the new proposal would provide significantly less money than Biden initially requested.

It allocates $1 billion for a fund to reconnect communities divided by transportation construction in the 20th century, far less than the $25 billion in the original White House pitch. Funding for electric-vehicle infrastructure would amount to $7.5 billion, with another $7.5 billion for electric buses, down from a combined $40 billion. The White House says even the smaller sum for charging infrastructure would be enough to meet its goal of installing 500,000 outlets across the country.

Jeff Davis, a fellow at the policy analysis group Eno Center for Transportation, calculated that when it comes to road, rail and transit spending, the framework proposes about $16 billion more than a transportation bill advancing through the House. (The Senate is considering a similar bill, but hasn’t set a funding level for transit.)

The American Society of Civil Engineers, which produces an influential rating of the nation’s infrastructure, said the new framework was encouraging and could help address what it assesses to be a $2.59 trillion shortfall in needed spending over the next decade.

The Biden administration has framed its transportation plans as a once-in-a-generation opportunity to reshape how people get around. Many bridges and highways are reaching the end of their life span and need to be replaced or overhauled. At the same time, transportation is the nation’s biggest source of greenhouse gas emissions, with electric vehicles slowly taking hold. Communities of color and poorer neighborhoods often suffer from fewer transportation options, limiting access to jobs and health care.

Details on how the money would be spent were limited — specifics that some analysts cautioned Thursday could alter the agreement’s ability to reach Biden’s goals of helping the environment and making the transportation system more equitable.

“What policy is attached to these expenditures?” said Kevin DeGood, director of infrastructure policy at left-leaning think tank the Center for American Progress. “That matters a great deal.”

He pointed to a transportation bill written by House Democrats, which would require states to consider transit and other options before expanding their road networks, while holding them accountable for reducing greenhouse gas emissions from transportation.

A Senate committee’s version of the bill would set fewer restrictions on spending, but it passed unanimously out of committee.

Paul P. Skoutelas, president of the American Public Transportation Association, praised the bipartisan group’s latest effort Thursday while also reiterating the organization’s support for the House bill.

“Our nation demands forward-looking infrastructure investment that modernizes public transit and passenger rail systems and meets the growing and evolving mobility demands of communities,” he said.

Although some senators involved in negotiations floated fees on drivers as one way to cover the cost of new spending, the package steers clear of changes to the gas tax or fees on electric vehicles.

Next steps for the proposal weren’t clear Thursday. Lawmakers could fold the additional money into existing transportation spending bills in Congress or write a separate piece of legislation. Biden and House Speaker Nancy Pelosi (D-Calif.) have said they want the bipartisan package to also advance alongside a budget bill that would not need Republican votes in the Senate, which could be used to fulfill other Democratic objectives.