Transportation advocates will descend on Washington Monday to kick off “infrastructure week” without a clear picture of what President Trump’s massive rebuilding package will look like.

But even though the timing and funding offsets for the proposal remain up in the air, other key details have begun to take shape.

Here are five things we know so far about the White House push to upgrade U.S. roads, bridges, airports and other public works. 

Price tag

Trump has repeated an eye-popping price tag for his infrastructure plan: $1 trillion.

He has even suggested that the final level of investment could top that figure.

“We’re talking about a very major infrastructure bill for $1 trillion, perhaps even more,” Trump said during a recent town hall-style event with American business CEOs.

But the actual cost of the bill will be far less, as the administration plans to bring more private sector dollars off the sidelines in order to help make transportation upgrades. 

The White House said it would use around $200 billion in taxpayer dollars for the national rebuilding plan, according to Mick Mulvaney, director of the Office of Management and Budget.

“We’re certainly going to spend some money,” Mulvaney said at an event sponsored by the Institute of International Finance last month. “The president wants a trillion dollars’ worth of work on the ground and we’re going to give it to him.”

Cutting red tape 

One of the chief priorities for the administration is cutting the so-called regulatory red tape that can slow down transportation projects. 

Transportation Secretary Elaine Chao has said that the “problem is not money,” it’s how long it takes for construction permits to get approved.

“Investors say there is ample capital available, waiting to invest in infrastructure projects,” Chao said at the American Association of Port Authorities conference last month. “So the problem is not money. It’s the delays caused by government.”

The infrastructure plan is certain to take aim at the lengthy permit approval process, which Trump said can take up to 10 years.  

The president said in a recent speech to builders that he wants to streamline the permitting process so that it only takes one year.

Trump even brought out a giant chart, something he has done on more than one occasion, to visually illustrate all the regulations that must be complied with to build highways.

“If you want to build a highway in the United States, these are some of the permits you need,” Trump said, holding the chart. “It’s a process that can take way over 10 years and just never happens. We’re getting rid of many of these regulations.” 

Public-private partnerships

Private financing was the cornerstone of the infrastructure proposal that Trump floated on the campaign trail. The idea behind that plan was to offer $137 billion in tax credits to private investors who back transportation projects.

Since taking office, Trump has told Congress his infrastructure plan will be “financed through both public and private capital.” 

But Trump’s infrastructure plan is still expected to focus heavily on public-private partnerships, the funding tool generally preferred by Republicans. They argue that putting the private sector in charge of infrastructure projects can help bring down costs and speed up delivery.

The ratio of private sector money to federal funding in the package is expected to be about 5-to-1, according to Trump’s budget chief.

But that could draw the ire of Democrats and rural Republicans, who worry that private firms would only be attracted to large-scale projects that can recoup their investment costs through toll ways or user fees. 

Shovel-ready

Trump, whose business career revolved around real estate and construction, wants his infrastructure plan to be implemented quickly once it’s signed into law.

He told The New York Times last month that he wants to give projects 120 days to get started in order to receive any federal funding. Trump had previously floated the idea of giving projects a 90-day deadline.

“When we do the infrastructure, it’s going to be very important to me that if we give billions of dollars to a state, like New York, California or any other state, that they’re going to have to start spending that money, they’re going to have to have approval within 120 days,” Trump said. 

But the idea of “shovel-ready” projects is hardly new, and it could create headaches for the administration if projects end up running into delays.

One of the critiques of former President Obama’s 2009 economic stimulus package was that the “shovel-ready” transportation projects in the bill took too long to get off the ground.

Broad range of projects

The comprehensive rebuilding plan is likely to tackle a broad range of infrastructure projects, including boosting broadband and rehabilitating veterans hospitals.

“The proposal will cover more than transportation infrastructure,” Chao said at her welcoming ceremony. “It will include energy, water, and potentially broadband and veterans hospitals as well.” 

The potential inclusion of veterans hospitals was a new development that the administration revealed in late March.

“There are some unique needs, especially when you think about veterans hospitals,” DJ Gribbin, special assistant to the president for infrastructure policy, told The Hill last month. “Is there a way to incorporate maybe a public-private partnership concept in serving veterans and providing them with better healthcare?” 

Rural lawmakers have also been urging the administration to include funding tools that will help improve broadband access and other issues that are unique to their communities. Earlier this year, rural broadband and farm groups sat down with White House staff to offer suggestions for the package.

National Economic Council director Gary Cohn said the infrastructure package would also include “transformative” projects, such as modernizing the system’s air traffic control system.

“Air traffic control is probably the single most exciting thing we can do,” Cohn said.