What to know about this weekend's IndyCar race on the streets of the nation's capital

Start your engines. President Donald Trump is transforming the streets around the National Mall in Washington, D.C., this weekend into an IndyCar motorsports mecca for the first time.

IndyCars will zoom around a 1.66-mile track against the backdrop of some of the most iconic buildings in the nation. The main straightaways will be Pennsylvania Avenue and Independence Avenue, where drivers will rev their race cars to speeds more than seven times faster than the normal speed limit of 25 mph.

The 250-mile race, or 147 laps around the track, is expected to take about 3 hours to finish and will be broadcast live on Fox.

Numerous streets around the National Mall will be closed over the weekend, and concrete guard barriers and fencing have been erected along the race course to protect fans and property. Risers for spectators to view the race and bridges for people to get around have been constructed.

Organizers of the race have said they have also resurfaced the roadways being used for the track and have welded more than 200 manhole covers shut to prevent them from flying off during the race.

Trump is hosting the Freedom 250 Grand Prix as part of a series of celebrations of the country's 250th birthday. The event is being run through the Freedom 250 Grand Prix organization, which said on its website that it is "supported by a group of key partners," including IndyCar's "promotional alliance with Monumental Sports & Entertainment."

But the race is not without controversy. A preservationist group has raised concerns that vibrations from the race could damage priceless frescoes at one of the historic buildings on the race course.

The two-day free event is scheduled to begin on Saturday with practice runs, an NTT IndyCar Series qualifying run and an International Race of Champions Racing Series (IROC) event.

The main event will occur on Sunday with the Freedom 250 Grand Prix of Washington, D.C., beginning around 1:10 p.m. ET with the green flag start of the race on 3rd Street in front of the U.S. Capitol Building.

"This will be like no other race ever. This will get the highest ever ratings of any such race," Trump said in July, when he invited the top IndyCar drivers who will participate in the race to the White House.

The event is expected to draw about 140,000 spectators on each day of the event. About 100,000 free tickets have been handed out through a lottery.

Many of the top Indy racers are expected to participate, including Felix Rosenqvist, winner of the 2026 Indianapolis 500.

Trump signed an executive order on Jan. 30, clearing the way for the race, writing in the order that it will "showcase the majesty of our capital city in celebration of the 250th anniversary of America's independence."

"You're going to see cars at a level they've never been at before, with cars racing more than 190 mph, and even higher than that, down Pennsylvania Avenue," Trump said in July.

But such speeds and torque of the race cars' twin-turbocharged V-6 engines have a group of historic preservationists worried.

The Living New Deal -- a nonprofit and non-partisan organization dedicated to preserving the history of President Franklin Delano Roosevelt's series of economic, social and political reforms -- is raising concerns about the race.

Mary Okin, assistant director of the Living New Deal, told ABC News that her group is particularly worried that vibrations from the race cars will damage the historic frescoes at the entrance of the Wilbur J. Cohen Building.

The Cohen Building originally housed the Social Security Administration, an important piece of the New Deal legacy, and contains frescoes painted in the 1940s by famed artist Seymour Fogel on the entrance lobby walls, Okin said.

The Cohen Building's entrance sits near one of seven turns featured in the Grand Prix race course, Okin said.

"It has become clear to us that this event would include substantial potential for adverse effects due to vibratory impacts likely with sound waves in excess of 130 dB [decibels] during the race," Okin wrote in a letter she sent last month to the U.S. General Services Administration (GSA), which manages the Cohen Building.

"In the foreseeable event of a race vehicle losing control, or a crash that sends debris, such as tire marbles flying, or sparks a fire, what protective features will be in place ahead of the race to ensure that vibration, flying car parts, and other high speed or collision impacts do not damage this national treasure?" Okin wrote.

Okin said she received a response from the GSA saying it would conduct a post-race damage assessment of the Cohen building.

"To me, everything about this is really problematic," Okin told ABC News. "Car races can happen anywhere. This is not an ideal area for that. Why is this happening at all? It would not happen under any other administration."

In a statement to ABC News on Wednesday, a GSA spokesperson said that the agency reviewed the race course "for potential impact on our nearby assets and identified no areas of concern."

"Like millions of other Americans, we fully support the patriotic celebrations happening in our Nation's capital, including the Freedom250 Grand Prix," the GSA spokesperson said.

The National Parks Service, which issued the permits for the race, declined to comment and directed questions from ABC News about the event to organizers of the Freedom 250 Grand Prix.

A spokesperson for the Freedom 250 Grand Prix said in a statement that IndyCar has "tremendous respect for the history and the structures" along the race track.

"INDYCAR has successfully hosted races on downtown street circuits in urban areas for decades," the statement said. "With this excellent track record and the thorough preparation we have done for this event, we do not anticipate any impact on the structures surrounding the circuit as a result of the racing activity at the upcoming Freedom 250 Grand Prix."

Several major museums are also situated alongside the race course, including the National Archives, the National Museum for the American Indian, the Smithsonian Air and Space Museum and the National Gallery of Art.

Chris Abanavas, a spokesperson for the National Gallery of Art, told ABC News that in preparation for the Freedom 250 Grand Prix, the gallery conducted "an extensive vibration study."

Abanavas said in a statement that based on the results of the study, "we have implemented a set of measures to ensure the safety of our staff, visitors, collection, and facilities during the race."

Abanavas added, "While we are not releasing the specifics, I can share that any such measures are only being taken out of a great abundance of caution."