Passenger rail could be the big winner if Congress moves ahead with President Biden's ambitious infrastructure plan.

Why it matters: There's long been bipartisan support for rebuilding America's crumbling infrastructure, but under Biden, the focus has shifted to sustainable projects that fulfill both his climate and equity goals, such as rail transit.

• Even though many public transit systems are reeling from the pandemic, ridership is expected to return eventually, requiring long-term investment.

Driving the news: Right now, the Biden administration is trying to get his $1.9 billion COVID stimulus package through Congress (including $30.5 billion in emergency funding for public transit). But soon the House and Senate will turn their attention to infrastructure spending.

• Biden wants to spend $2 trillion, including $50 billion on immediate road and bridge repairs.
• He also wants to build out transit in high-poverty areas and fund high-speed rail systems, promising "the second great railroad revolution."
• The price tag could be too high for Republicans, but Senate Budget Committee Chair Bernie Sanders told Axios that Democrats will pass it with a simple majority through the budget reconciliation process if necessary.
• Reality check: That could work, but only as long as moderate Democratic senators don't balk at the price tag, too.

The big picture: Rail advocates see a rare opportunity to go big with "Amtrak Joe" in the White House.

• "The stars don’t often align in the federal government, and we are at this moment where the White House, the House and the Senate are all in agreement that this is the time to dramatically increase investment in infrastructure," said Sean Jeans-Gail, vice president of policy and government affairs for the Rail Passengers Association.
• "And passenger rail, a transportation mode that is traditionally ignored in the United States, has more to gain than other modes," he added.

Details: For starters, there is plenty of "low-hanging fruit" like installing better signaling equipment, updating rail stations and deploying modern train cars on existing lines like Amtrak's Northeast Corridor, Gail said.

• A handful of high-speed rail projects could also get a boost, including the $105 billion North Atlantic Rail project connecting New York and Boston.
• Jockeying has already begun among backers of various high-speed rail projects, including current and proposed systems in California, Texas, Florida and the Pacific Northwest, writes Bloomberg City Lab.
• Rep. Seth Moulton (D-Mass.) is pushing a bill that would invest $205 billion over five years on a high-speed rail network, creating at least 2.6 million new jobs and connecting city pairs that in some cases airlines have abandoned.
• "We have a once-in-a-generation chance to invest in infrastructure America will use for the next 100 years," Moulton tells Axios. "We can't squander this opportunity by buying the last generation’s infrastructure."

Within cities, meanwhile, new light-rail systems could help ease traffic and promote economic growth, as they have in places like Seattle and Denver.

• In Charlotte, where 400,000 new residents are expected to move by 2040, light-rail plays a critical role in an ambitious transportation plan that could cost $8 billion to $12 billion, Axios Charlotte reports.

Yes, but: To ensure transportation equity, planners need to get buy-in from affected residents, said Paul Skoutelas, CEO of American Public Transportation Association.

• "The decision-making process has to be inclusive," he said. "You have to make sure the professionals are listening carefully to the users to understand how they are going to impact a community."